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BIOLOGY, CLASS-XI, Members of Review Committee, S.No., , Name, , 1. Dr. Ravinder Kumar, , , Designation, , School, , Vice, Principal, , G.Co.Ed. Sr. Sec. School,, Sector-2, Rohini, Delhi., , 2., , Dr. Anita, , Lecturer, , RPVV, Dwarka, Sector-10,, Delhi., , 3., , Sh. Rajendra Singh, , Lecturer, , G.Co.Ed. Sr. Sec. School, , Sector-2, Rohini, Delhi., , 4., , Mr. Pawan Kumar, , Lecturer, , RPVV, Sector-XI, Rohini,, Delhi, , i
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9. BIOLOGY (Code No. 044), The present syllabus reinforces the ideas introduced till the secondary classes., It provides the students with new concepts along with an extended exposure to, contemporary areas of the subject. The syllabus also aims at emphasizing on, the underlying principles that are common to both animals and plants as well as, highlighting the realtionship of biology with other areas of knowledge.The format, of the syllabus allows a simple, clear, sequential flow of concepts without any, jarring jumps. The syllabus also stresses on making better connections among, biological concepts. It relates the study of biology to real life through the use of, technology. It links the discoveries and in novations in biology to everyday life, such as environment, industry, health and agriculture. The updated syllabus also, focuses on reducing the curriculum load while ensuring that ample opportunities, and scope for learning and appreciating basic concepts of the subject continue to, be available within its framework. The prescribed syllabus is expected to :, , , , , , , , , , , , Promote understanding of basic principles of Biology, Encourage learning of emerging knowledge and its relevance to individual, and society, Promote rational/scientific attitude towards issues related to population,, environment and development, Enhance awareness about environment issues, problems and their, appropriate solutions., Create awareness amongst the learners about diversity in the living, organisms and developing respect for other living beings, Appreciate that the most complex biological phenomena are built on, essentially simple processes, , It is expected that the students would get an exposure to various branches of, Biology in the syllabus in a more contextual and friendly manner as they study, its various units., , ii
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Time : 3 Hours, , BIOLOGY (Code No. 044), Course Structure, Class XI (2017-18), (Theory), , Unit , , Title, , Max. Marks : 70, , No. of Periods, , Marks, , I, , Diversity of Living Organisms, , 23, , 07, , II, , Structural Organisation in Plants and Animals, , 22, , 12, , III, , Cell : Structure and Function, , 35, , 15, , IV, , Plant Physiology, , 40, , 18, , V, , Human Physiology, , 40, , 18, , 160, , 70, , Total, , Unit–I Diversity of Living Organisms, 23 Periods, Chapater–1 : The Living World, What is living ? Biodiversity; Need for for classification; three domains of, life : taxonomy and systematics; concept of scpecies and taxonomical hierarchy;, binomial nomenclature; tools for study of taxonomy-museum, zoological parks,, herbaria, botanical gardens., Chapter–2 : Biological Classification, Five kingdom classificatigon; Salient feataures and classificaiton of, Monera,Protista and Fungi into major groups; Lichens,Viruses and Viroids., Chapter–3 : Plant Kingdom, Salient features and classification of plants into major groups – Algae,, Bryophyta, Pteriodophyta, Gymnospermae and Angiospermae (three to five, salient and distinguishing features and at least two examples of each category);, Angiosperms –classification upto class , characteristic features and examples., Chapter–4 : Animal Kingdom, Salient features and classification of animals non-chordates up to phyla level, and chordates up to class level (three to five salient features and at least two, examples of each category)., (No live animals or specimen should be displayed.), iii
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Unit–II Structural Organisation in Animals and Plants, , 22 Periods, , Chapter–5 : Morphology of Flowering Plants, Morphology and modfications : Tissues, Chapter–6 : Anatomy of Flowering Plants, Anatomy and functions of different parts of flowering plants : root, stem,, leaf, inflorescence, flower, fruit and seed (to be dealt along with the relevant, experiment of the Practical Syllabus)., Chapter–7 : Structural Organisation in Animals, Animal tissues : Morphology, anatomy and functions of different systems, (digestive, circulatory, respiratory, nervous and reproductive) of an insect, (cockroach), (a brief account only), Unit–III Cell : Structure and Function, , 35 Periods, , Chpater–8 : Cell-The Unit of Life, Cell theory and cell as the basic unit of life : Structure of prokaryotic and, eukaryotic cells; Plant cell and animal cell; cell envelope; cell membrane, cell, wall; cell organelles–structure and function; endomembrane system, endoplasmic, reticulum, Golgi bodies, lysosomes, vacuoloes; mitochondria, ribosomes, plastids,, microbodies; cytoskeleton, cilia, flagella, centrioles (ultrastructure and function);, nucleus, nuclear membrane, chromatin, nucleolus., Chapter–9 : Biomolecules, Chemical constituents of living cells : biomolecules, structure and function of, proteins, carbohydrates, lipids, nucleic acids, enzymes, types, properties, enzymes, action., Chapter–10 : Cell Cycle and Cell Division, Cell cycle, mitosis, meiosis and their significance., Unit–IV Plant Physiology, , 40 Periods, , Chapter–11 : Transport in Plants, Movement of water, gases and nutrients; cell to cell transport, Diffusion,, facilitated diffusion, active transport; plant-water relations, Imbibition, water, potential, osmosis, plasomlysis; long distance transport of water–Absorption,, iv
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apoplast, symplast, trranspiration pull, root pressure and guttation; transpiration,, opening and closing of stomata; Uptake and translocation of mineral nutrients–, Transport of food, phloem transport, massflow hypothesis; diffusion of gases., Chapter–12 : Mineral Nutrition, Essential minerals, macro-and micronutrients and their role; deficiency, symptoms; mineral toxicity; elementary idea of hydroponics as a method to study, mineral nutrition; nitrogen metabolism, nitrogen cycle, biological nitrogen fixation., Chapter–13 : Photosynthesis in Higher Plants, Photosynthesis as a mean of autotrophic nutrition; site of photsynthesis,, pigments involved in photosynthesis (elementary idea); photochemical and, biosynthetic phases of photo-synthesis, cyclic and non cyclic photophosphorylation;, chemiosmotic hypothesis; photorespiration; C3 and C4 pathways; factors affecting, photoshynthesis., Chapter–14 : Respiration in Plants, Exchange of gases; cellular respiration–glycolysis, fermentation (anaerobic),, TCA cycle and electron transport system (aerobic); energy relations–number of, ATP molecules generated; amphibiotic pathways; respiratory quotient., Chapter–15 : Plant–Growth and Development, Seed germination; phases of plant growth and plant growth rate; conditions, of growth; differentiation, dedifferentiation and redifferentiation;’ sequence of, developmental processes in a plant cell; growth regulators–auxin, gibberellin,, cytokinin, ethylene, ABA; seed dormancy; vernalisation; photoperiodism., Unit–V Human Physiology, , 40 Periods, , Chapter–16 : Digestion and Absorption, Alimentary canal and digestive glands, role of digestive enzymes and, gastrointestinal hormones; Peristalsis, digestion, absorption and assimilation of, proteins, carbohydrates and fats; calorific values of proteins, carbohydrates and, fats; egestion; nutritional and digestive disorders–PEM, indigestion, constipation,, vomiting, jaundice, diarrhoea., v
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Chpater–17 : Breathing and Exchange of Gases, Respiratory organs in animals (recall only); Respiratory system in human;, mechanism of breathing and its regulation in humans–exchange of gases, transport, of gases and regulation of respiration, respiratory volume; disorders related to, respiration–asthma, emphysema, occupational respiratory disorders., Chapter–18 : Body Fluids and Circulation, Composition of blood, blood groups,coagulation of blood; composition of, lymph and its function; human circulatory system–structure of human heart and, blood vessels; cardiac cycle, cardiac output, ECG; double circulation; regulation, of cardiac activity; disorders of circulatory system–hypertension, coronary artery, disease, angina pectoris, heart failure., Chapter–19 : Excretory Products and Their Elimination, Modes of excretion–ammontelism, ureotelism, uricotelism; human excretory, system–structure and function; urine formation, osmoregulation of kidney function–, renin–angiotensin, atrial natriuretic factor, ADH and diabetes insipidus; role of, other organs in excretion;’ disorders– uraemia, renal failure, calculi, nephritis;, dialysis and artificial kidney., Chapter–20 : Locomotion and Movement, Types of movement–Ciliary, flagellar, muscular; skeletal muscle–contractile, proteins and muscle contraction; skeletal system and its functions; joints; disorders, of muscular and skeletal system–myasthenia gravis, tetany, musuclar dystrophy,, arthritis, osteoporosis, gout., Chapter–21 : Neural Control and Coordination, Neuron and nerves;Nervous system in humans–central nervous system;, peripheral nervous system and visceral nervous system; generation and conduction, of nerve impulse; reflex action; sensory perception sense organs;elementary, structure and functions of eye and ear., , vi
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Chpater–22 : Chemical Coordination and Integration, Endocrine glands and hormones; human endocrine system–hypothalamus,, pituitary, pineal, thyroid, parathyroid, adrenal, pancreas, gonads; mechanism of, hormone action (elementary idea); role of hormones as messengers and regulators,, hypo–and hyperactivity and related disorders; dwarfism, acromegaly, cretinism,, goiter, exopthalmic goiter, diabetes, Addision’s disease., Note—Diseases related to all the human physiological systems to be taught, in brief., , vii
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Practicals, Time Allowed : Three hours, , Max.Marks : 30, , Evaluation Scheme, One Major Experiment Part A (One from Experiment No. 1,3,7,8) 5 Marks, One Minor Experiment Part A, 4 Marks, (One from Experiment No. 6,9,10,11,12,13), , Slide Preparation Part A (One from Experiment No. 2,4,5), Spotting Part B, Practical Record + Viva Voce, Project Record + Viva Voce, Total, A. List of Experiments, , 5 Marks, 7 Marks, 4 Marks, 5 Marks, 30 Marks, 60 Periods, , 1. Study and description of three locally available common flowering plants,, one from each of the families Solanaceae, Fabacceae and Liliaceae, including dissection and display of floral whorls, anther and ovary to show, number of chambers (floral formulae and floral diagrams). Types of root, (Tap and adventitious); stem (herbaceous and woody); leaf (arrangement,, shape,venation, simple and compound)., 2. Preparation and study of T.S. of dicot and monocot roots and stems (primary)., 3. Study of osmosis by potato osmometer., 4. Study of plasmolysis in epidermal peels (e.g. Rhoeo leaves)., 5. Study of distribution of stomata in the upper and lower surface of leaves., 6. Comparative study of the rates of transpiration in the upper and lower surface, of leaves., 7. Test for the presence of sugar, starch, proteins and fats. Detection in suitable, plant and animal materials., 8. Separation of plant pigments through paper chromatography., 9. Study of the rate of respiratioin in flower buds/leaf tissue and germinating, seeds., 10. Test for presence of urea in urine., 11. Test for presence of sugar in urine., 12. Test for presence of albumin in urine., 13. Test for presence of bile salts in urine., viii
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B. Study/observation of the following (spotting), 1. Study of the parts of a compound microscope., 2. Study of the specimens/slides/modles and identification with reasons–, Bacteria, Oscillatoria, Spirogyra, Rhizopus, mushroom, yeast, liverwort,, moss, fern, pine, one monocotyledonous plant, one dictoyledonous plant, and one lichen., 3. Study of virtual specimens/slides/models and identification with, reasons–Amoeba, Hydra, liverfluke,Ascaris,leech, earthworm, prawn,, slikworm,honeybee,snail, starfish, shark, rohu, frog, lizard, pigeon and rabbit., 4. Study of tissues and diversity in shapes and sizes of plnat and animal cells, (palisade cells, guard cells, parenchyma, collenchyma, sclerenchyma, xylem,, phloem, suquamous epithelium, muscle fibers and mammalian blood smear), through temporary/permanent slides., 5. Study of mitosis in onion root tip cells and animals cells (grasshopper) from, permanent slides., 6. Study of different modifications in roots, stems and leaves., 7. Study and identification of different types of inflorescence (cymose and, racemose)., 8. Study of imbibition in seeds/raisins., 9. Observation and a comments on the expeirmental set up for showing :, (a) Anaerobic respiration, (b) Phothotropism, (c) Effect of apical bud removal, (d) Suction due to transpiration, 10. Study of human skeleton and different types of joints with the help of virtual, images/models only., 11. Study of external morphology of cockroach through virtual images/models., Practical Examination for Visually Impaired Students, Class XI, Note : Same Evaluation scheme and general guidelines for visually impaired, students as given for Class XII may be followed., A. Items for Identification/Familiarity with the apparatus/equipments/, animal and plant material/chemicals etc. for assessment in practicals, (All experiments), Plants of—, , Solanaceae–Bringal, Petunia, any other, , Fabaceae–Rice, Wehat, any other, , Liliaceae–Any of the Lilies, ix
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A compound microscope, seeds of monocot and dicot–maize and gram or, any other Model of Human skeleton to show., , Ball and socket joints of girdles and limbs, , , Rib cage, , Test tube, honey comb, Mollusc shell, Models of Pigeon and Star fish,, mushroom, petridish, succulents such as Aloe vera/kalenchoe, raisins, beaker,, potatoes, scalpel, chromatography paper, chromatography chamber, alcohol,, specimen/model of cockroach., B. List of Practicals, 1. Study three locally available common flowering plants of the families–, Solanaceae, fabaceae, Liliaceae and identify :, , Types of roots as Tap and Adventitious, , , Types of stems as Herbaceous or Woody, , , Types of leaves as Compound or Simple, , 2. Study the parts of a compund microscope–eye piece and objective lense,, mirror, stage, coarse and fine adjustrment knobs., 3. Differentiate between monocot and dicot plants on the basis of venation, patterns., 4. Study the following parts of human skeleton (Model);, , Ball and socket joints of thigh and shoulder, , , Rib cage, , 5. Study honey bee through comb, snail through shell,Starfish through model,, Pigeon through model., 6. Identify the given specimen of a fungus–Mushroom., 7. Study the adaptive features of xerophytic plants., 8. Study the process of osomosis through endosomosis in raisins., 9. Identify and releate the given experimental set up with aim of experiment :, , Paper Chromatography, , or, , Potato Osmometer, , 10. Study the external features/morphology of cockroach through model, Note : The above practicals may be carried out in an experimental manner rather, than recording observations., Prescribed Books :, 1. Biology Class-XI, Published by NCERT, 2. Other related books and manuals brought out by NCERT (consider multimedia, also), x
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BIOLOGY (Code No. 044), Question Paper Design, Class-XI (2016–17), Time : 3 Hours, S. Typology of Questions, No. , , , , Max. Marks : 70, Very, Short, short Answer-I, Answer (SA–I), , Short, Answer-II, (SA-II), , Value, based, question, , Long, Answer, (LA), , (VSA) (2 marks), , (3 marks) (4 marks) (5 marks), , Total, Marks, , %, Weightage, , (1 marks), , Remembering–(Knowedge, 1. , based Simple recall questions, to know specific facts,, terms, concepts, prin- ciples,, or theories, Identify, define,, or recite, information), Understanding–(Com2. , prehension–To be familiar with meaning and to, understand conceptually,, interpret,compare,contrast,, explain , paraphrase information), 3. , Application (Use abstract, information in concrete, situation, to apply knowledge to new situations,, Use given content to interpret a situation, provide, an example, or solve a, problem), 4. , High Order Thinking, Skills (Analysis & Synthesis–Classify, Compare,, Contrast, or differentiate, between different pieces, of information, Organize, and/or integrate unique, pieces of information from, a variety of sources), 5. , Evaluation–(Appraise,, judge, and/or justify the, value or worth of a decision, or outcome,or to predict, outcomes based on values), , TOTAL, , 2, , 1, , 1, , –, , –, , 7, , 10%, , –, , 2, , 4, , –, , 1, , 21, , 30%, , –, , 2, , 4, , –, , 1, , 21, , 30%, , 2, , –, , 1, , –, , 1, , 10, , 14%, , 1, , –, , 2, , 1, , –, , 11, , 16%, , 5×1=5, , 5×2=10, , 12×3=36, , 1×4=4, , 3×5=15, , 70(26), , 100%, , xi
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Question Wise Break Up, Types of, , Mark(s) per, , Total No. of, , Total, , Question, , Question, , Questions, , Marks, , VSA, , 1, , 5, , 05, , SA-I, , 2, , 5, , 10, , SA-II, , 3, , 12, , 36, , VBQ, , 4, , 1, , 04, , LA, , 5, , 3, , 15, , 26, , 70, , Total , , 1. Internal Choice : There is no overall choice in the paper. However, there is, an internal choice in one in one question of 2 marks weightage, one question, of 3 marks weightage and one question of 5 marks weightage (Content based, question)., 2. The above template is only a sample. Suitable internal variations may be, made for generating similar templates keeping the overall weightage to, different form of questions and typology of questions same., , xii
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BIOLOGY – XI, Index, S. No., , Chapter Name, , Page No., , 1., , The Living World, , 15 - 19, , 2., , Biological Classification, , 20 - 28, , 3., , Plant Kingdom, , 29 - 36, , 4., , Animal Kingdom, , 37 - 46, , 5., , Morphology of Flowering Plants, , 47 - 60, , 6., , Anatomy of Flowering Plants, , 61 - 72, , 7., , Structural Organization in Animals, , 73 - 82, , 8., , Cell : The Unit of Life, , 83 - 90, , 9., , Biomolecules, , 10., , Cell Cycle and Cell Division, , 101 - 108, , 11., , Transport in Plants, , 109 - 120, , 12., , Mineral Nutrition, , 121 - 130, , 13., , Photosynthesis in Higher Plants, , 131 - 141, , 14., , Respiration in Plants, , 142 - 150, , 15., , Plant Growth and Development, , 151 - 158, , 16., , Digestion and Absorption, , 159 - 167, , 17., , Breathing and Exchange of Gases, , 168 - 176, , 18., , Body Fluids and Circulation, , 177 - 186, , 19., , Excretory Products and their Elimination, , 187 - 194, , 20., , Locomotion and Movement, , 195 - 202, , 21., , Neural Control and Coordination, , 203- 211, , 22., , Chemical Coordination and Integration, , 212- 220, , Practice paper with Solution, , 221 - 238, , , , 91 - 100, , xiii
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xiv
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Points to Remember, 1. Organism (Microorganism, plant and animals) who posses life is living., 2. Life is a complex organisation expressing itself through chemical reactions, and exhibit characteristics of living organisms., 3. Characteristics of Living Organisms : Growth, reproduction, metabolism,, cellular organisation, consciousness (ability to sense environment), selfreplicating and self regulation., Reproduction and growth are NOT defining properties., , , Metabolism, cellular organisation and consciousness are defining, properties., , Living organisms are self-replicating, evolving, self-regulating and, interactive systems capable of responding to external stimuli., 4. Biodiversity : Term used to refer to the variety of microorganisms, plant, and animals on earth., 5. Need for classification : To organise the vast number of microorganisms,, plants and animals into categories that could be named, remembered, studied, and understood., 6. Three Domains of Life : Proposed by Carl Woese in 1990 who also proposed, the six kingdom classification for living organisms. The three Domains of, life are Archaea, Bacteria and Eukarya., , 1 , Kingdom, , Archaea → 1. Archaebacteria, , 2, , Domains, Bacteria → 2. Eutacteria, , of life, 3, , Eukarya → 3. Protista, → 4. Fungi, , → 5. Plantae, , → 6. Animalia, , The Living World, , 15
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7. Taxonomy : Study of principles and procedures of identification, nomenclature, and classification., 8. Systematics : It deals with classification of organisms based on their, diversities and relationships among them. Term was proposed by Carolus, Linnaeus who wrote ‘Systema Naturae’., 9. Concept of Species : All the members that can interbreed among themselves, and can produce fertile offsprings are the members of same species. This is, the biological concept of species proposed by Mayr., 10. Taxa : Each category (i.e., unit) of classification is called as a taxon., 11. Taxonomic Hierarchy : Classification of organisms in a defnite sequence, of taxon or category or rank in a desending order., Kingdom → Phylum /Division → Class → Order → Family → Genus → Species., , 12. Binomial Nomenclature : Given by Carolus Linnaeus. Each scientific name, has two components-Generic name + Specific epithet., 13. ICBN : International Code for Botanical Nomenclature (for giving scientific, name to plants.), 14. ICZN : International Code of Zoological Nomenclature (for giving scientific, name to animals.), 15. Rule for Nomenclature :, Latinised names are used., , First word is genus, second word is species name., , , Printed in italics; if handwritten then underlined separately., , , First word starts with capital letter while species name written in small, , letter., 16. Scientific names of some organisms :, Man , —, Homo sapiens, Housefly, —, Musca domestica, Mango, —, Mangifera indica, Wheat , —, Triticum aestivum, 17. Taxonomical Aids are the tools for study of taxonomy., 18. Museums in educational institutes (school and colleges) have collection of, skeletons of animals, stuffed and preserved specimens of organisms for study, and reference., 19. Zoological Parks (Places where wild animals are kept in protected environment, under human care) Example : National Zoological Park, Delhi., 20. Herbarium : Store house of dried, pressed and preserved plant specimen, on sheets, kept systematically according to a widely accepted system of, classification, for future use., 16, , Biology Class - 11
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21. Botanical Garden : Collection of living plants for reference., , Example : Royal Batanical garden Kew (England), National Botanical, Research Institute (Lucknow), Indian Botanical Garden Howrah., 22., , , , Keys : (Used for indentification of plants and animals on the basis of similarities, and dissimilarities.), , 23. Couplet : are the two alternate characteristic statement used in key to identify, organisation., 24. Each Statement of the key is called a lead., 25., , , , 26., , , , 27., , , , Flora (Index to plant species found in a particular area., Manuals (Provide information for identification of name of species in an, area.), Mongoraphs (Contain information on any one taxon.), , Question, , Very Short Answer Question , , (1 mark each), , 1. Define species., 2. What is systematics ?, 3. Give the names of two famous botanical gardens., , Short Answer Question-I , , (2 marks each), , 4. What is the basis of modern taxonomical studies ?, 5. Why growth and reproduction cannot be taken as defining property of all, living organisms ?, 6. How is a taxon (pl. taxa) defined ?, , Short Answer Question-II (3 marks each), 7. What is the difference between Botanical Garden and Herbarium ?, 8. Keys are analytical in nature and are helpful in identification and classification, of organisms. How ?, 9. Define : (a) Genus , (b) Family, (c) Order, , Long Answer Questions , , (5 marks each), , 10. What are the universal rules of nomenclature ? What does ‘Linn.’ Refers to, in Mangifera indica Linn ?, The Living World, , 17
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11. Illustrate taxonomical hierarchy with suitable examples from plant and animal, species., 12. Define classification. What is the significance of classification ? What is the, six kingdom classification ?, , Answers, Very Short Answers , , (1 marks each), , 1. Members that can interbreed to produce fertile offspring., 2. Systematic arrangement which also takes into account evolutionary, relationships between organisms., 3. Kew (England) and National Botanical Research Institute (Lucknow), Indian, Botanical Garden (Howrah)., , Short Answers-I, , (2 marks each), , 4. External and internal structure, structure of cell, development process and, ecological information., 5., , , , Non-living things can also increase in mass by accumulation of material, on surface (accretion.), , , Many organisms do not reproduce (e.g., mules, sterile worker bees.), , , 6. Each category in a taxonomical hierarchy represents a rank and is called, taxon., , Short Answers-II , , (3 marks each), , 7. Botanical Garden : Collection of living plants., Herbarium : Collection of dried, pressed and prerserved plant specimens on, sheets., 8. Key is a list of alternate characters arranged in such a manner that by, acceptance and rejection one can easily identify an organisms as to its name, and position. Keys are generally analytical in nature., 9. (a) Genus : Group of related species;, (b) Family : Group of related genera;, (c) Order : Group of related families., 18, , Biology Class - 11
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Long Answers , , (5 marks each), , 10. Refer page no. 7, NCERT, Text Book of Biology for Class XI., ‘Linn.’ indicates that the species was first described by Linnaeus., 11. Refer table 1.1, page no. 11, NCERT, Text Book of Biology for Class XI., 12. Grouping organisms on the basis of their similarities and differences., Significance : – Aids in study, better understanding, predicting the features, of the group known., Refer ‘Points to Remember’ for six kingdom classification in three domains, of life., , , The Living World, , 19
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Points to Remember, Systems of Classification :, , , Earliest classification was given by Aristotle. Divided plants into herbs,, shrubs and trees., Animals into those with red blood and those who do not have it., , , , , , , , Two kingdom classification : Given by Carolous Linneaeus–Kingdom–, plantae and kingdom–Animalia., Five kingdom classification : By R.H. Whittaker, Monera, Protista, Fungi,, Plantae and Animalia are the five kingdoms., The main criteria for classification of organisms into five kingdoms include, cell structure, thallus organisation, mode of nutrition, reproduction and, phylogenetic relationships., , Kingdom Monera :, , , , , , , Has bacteria as sole members., Bacteria can have shapes like : Coccus (spherical), Bacillus (rod-shaped),, Vibrium (comma shaped) and spirillum (spiral shaped)., Bacteria found almost everywhere and can be Photosynthetic autotrophs,, Chemosynthetic autotrophs or Heterotrophs., , , , 20, , Archaebacteria, Bacteria, , Biology Class - 11, , Eubacteria
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, , Halophiles (salt-loving), , , , Thermoacidophiles (in hot springs), , , , , , , , , , , , , , Methanogens (in marsh and in gut of ruminant animals. Produce methane, gas.), Photosynthetic autotrophs like Cyanobacteria (Blue-green algae BGA)., Some like Anabaena and Nostoc have specialized cells called heterocysts, for nitrogen fixation., Algae bloom is rich growth of blue green algae over the surface of polluted, water bodies., Algae bloom releases neurotoxins, deplete oxygen and makes water unfit, for use., Chemosynthetic autotrophs : Oxidise various inorganic substances like, nitrates/nitrites, ammonia and use released energy for their ATP proudction., They helps in nutrients recycling of N, P, Fe and S., Heterotophic bacteria : Decomposers help in making curd, production of, antibiotic, N2 fixation, casuse disesaes like cholera, typhoid, tetanus and, citrus canker., , Mycoplasmas : Completely lack cell wall. Smallest living cells. Can survive, without oxygen. Pathogenic in animals and plants., , Kingdom PROTISTA, , (Comprises of all single celled eukaryotes), , , Forms a link between plants, animals and fungi., (i), , Chrysophytes (Has diatoms and golden algae/desmids), Fresh water/marine, photosynthetic, microscopic plankton., , , , , , , , , , , , , , Their accumulation forms ‘Diagomaceous Earth” (gritty soil), , , , , , Used in polishing, filtration of oils and syrups., , Chief producers in Ocean., Cell walls have silica which makes it indestructible and cell walls, overlap to fit together like a soap box., , Biological Classification, , 21
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(ii) Dinoflagellates :, , , , , , , , , , , , , Marine, photosynthetic, cell wall has stiff cellulose plates., Two flagella–one longitudinal and other transverse in a furrow, between wall plates., Example : Gonyaulax multiples rapdily, make sea appear red (red, tides) and produce toxins to kill marine animals., , (iii) Euglenoids :, , , , , Found in stagnant fresh water., Have protein rich layer ‘pellicle’ which makes body flexible., , , , , , , , , , Photosynthetic in presence of sunlight but become heterotrophs if, they do not get sunlight. (Mixotrophic nutrition), Example : Euglena, , , (iv) Slime Moulds :, , , , , , , , , , , , , , , , , Saprophytic protists, Under suitable conditions form an aggregates called plasmodium,, grows on decaying twigs and leaves., During unfavourable conditions, plasmodium differentiates and, forms fruiting bodies bearing spores at their tips., Spores have true walls which are extremely resistant and survive for, many years and dispersed by air currents., , (v) Protozoans : Are heterotrops and live as parasites. Have four major, groups., , , Amoeboid : Catch prey using pseudopodia, e.g., Amoeba. Entamoeba, are parasite., , , , Flagellated : Have one or more flagella. Cause disease like Sleeping, Sickness e.g., trypanosoma., , , , Ciliated : Have clilia to move food into gullet and help in locomotion., e.g., Paramoecium., , , , Sporozoans : Have infective spore like stage in life cycle, e.g.,, Plasmodium which causes malaria., , 22, , Biology Class - 11
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, , , , , , , , , , , Non-cellular organisms which take over the machinery of host cell on entering, it and become living but as such they have inert crystalline structure appear, non-living. So, difficult to call them living or non-living., Virus means venom or poisonous fluid. Pastuer gave the term ‘virus’., D.J. Ivanowsky found out that certain microbes caused Tobacco Mosaic, Disease in tobacco plant., M.W. Beijerinek called fluid as ‘Contagium vivum fluidum’ as extracts of, infected plants of tobacco could cause infection in healthy plants., W.M. Stanely showed viruses could be crystallized to form crystals of protein, which are inert outside their specific host., Viruses are obligate parasites., , Structure of Virus :, , , , , It is a nucleoprotein made up of protein coat called Capsid. Capsid is made, up of capsomeres arranged in helical or polyhedral-geometric forms. Have, either DNA or RNA as genetic material which may be single or double, stranded., Usually plant viruses have single stranded RNA; bacteriophages have double, stranded DNA and animal viruses have single or double stranded RNA or, double stranded DNA., , Diseases caused in humans :, Mumps, Small pox, herpes, influenza and AIDS etc. In plants, symptoms can, be mosaic formation, leaf rolling and curling, yellowing and vein clearing,, dwarfing and stunted growth., , Viroids :, , , Infectious agent, free RNA (lack protein coat), , , , RNA has low molecular weight., , , , Causes potato spindle tuber disease., , , , Discovered by T.O. Diener., , Lichens :, , , , , Symbiotic association between algal component (Phycobiont) and fungal, component (mycobiont). Algae provides food. Fungi provides shelter and, absorb nutrients and water for alga., Good pollution indicators as they do not grow in polluted areas., Biological Classification, , 25
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Questions, Very Short Answer Question, , (1 mark each), , 1. Nostoc and Anabaena have specialized cells called heterocysts. What is the, function of these cells ?, 2. Which group comprises of single celled eukaryotes only ?, 3. Which organisms are the chief producers in oceans ?, 4. Name the fungus which causes disease in wheat (i) rust (ii) smut., 5. Which Ascomycetes has been used extensively in biochemical and genetic, work ?, 6. What is the principle underlying the use of cyanobacteria in agriculture ?, , Short Answer Question-I , , (2 marks each), , 7. How are bacteria classified on the basis of their shapes ?, 8. What is the mode of reproduction in bacteria ?, 9. Why are red tides caused and why are they harmful ?, 10. Viruses and viroids differ in structure and the diseases they cause. How ?, 11. Which class of kingdom fungi has both unicellular as well as multicellular, member ? When is a fungus called coprophilous ?, , Short Answer Question-II , , (3 marks each), , 12. Who gave five kingdom classification ? What was the criteria used for such, classification ?, 13. What are the modes of nutrition in fungi ?, 14. Some symbiotic organisms are very good pollution indicators and composed, of a chlorophyllous and a non-chlorophyllous member. Describe them., , VBQ , , (4 marks), , 15. Vineeta went to the marked alongwith Roshan, her younger brother bought a, packet of mushroom. Roshan thinks that mushrooms is a product of plants., (a) What does Vineeta explain ?, 26, , Biology Class - 11
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(b) Name any two edible products from this group (scientific name.), (c) What values are displayed by Vineeta., , Long Answer Questions , , (5 mark each), , 16. Some primtive relatives of animals live as predators or parasites and are, divided into four major groups. Elaborate., 17. differentiate between various classes of kingdom Fungi on the basis of their, (i) Mycelium, (ii) Types of spores and (iii) Types of fruiting body. Also give, two examples for each class., 18. Describe sexual reproduction in fungi., , Answers, Very Short Answers , , (1 mark each), , 1. Help in nitrogen fixation., 2. Kingdom Protista., 3. Diatoms, 4. (i) Puccinia, (ii) Ustilago, 5. Neurospora, 6. Capability of nitrogen fixation, , Short Answers-I , , (2 marks each), , 7. Bacillus (rod-shaped), Coccus (spherical), Vibrio (comma shaped) and, Spirillum (spiral shaped)., 8. Mainly by fission; Production of spores in unfavourable conditions. Sexual, reproduction by DNA transfer., 9. Rapid multiplication of dinoflagellates like Gonyaulax. Harmful as they, release toxins which kill marine animals., 10. Refer ‘Points to Remember’., 11. Ascomycetes : Yeast (Unicellular), Penicillum (Multicellular), Coprophilous,, means fungi which grow on dung., Biological Classification, , 27
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Short Answers-II , , (3 marks each), , 12. R.H. Whittaker, Criteria for classification : Cell structure, thallus organisation,, mode of nutrition, reproduction and phylogenetic relationships., 13. Saprophytes, Parasites, Symbionts-Lichens and Mycorrhiza., 14. Lichens, Refer ‘Points to Remember’, , VBQ , , (4 marks each), , 15. (a) Mushrooms belong to Kingdom Fungi.They are saprotrophic, with cell, wall made of chitin-heterotrophs., (b) Agaricus, Morchella, (c) Scientific attitude, observant, will to disseminate knowledge to younger, people., , Long Answers , , (5 marks each), , 16. Protozoans. Refer page no 21-22, NCERT Text Book of Biology for Class, XI., 17. Refer NCERT Text Book of Biology for Class XI, Page no. 23-24., 18. Refer NCERT text book of Biology for Class XI Page 23. (Plasmogamy,, Karyogamy, Meiosis in zygote, Dikaryophase), The steps are :, (i) Plasmogamy : fusion of protoplasm of two motile or non-motile gametes., (ii) Kayogamy : fusion of two nuclei., (iii) Zygotic Meiosis to form haploid spores., (iv) Dikaryophase in ascomycetes and basidiomycetes where before, karyogamy two nuclei per cell (dikaryon) are found., , , 28, , Biology Class - 11
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Points to Remember, Classification :, , , Artificial System of Classification, , , By Carolus Linnaeus, based on androecium structure and vegetative, characters., , , Natural System of Classification, , Based on natural affinities among organisms, , , , Included external as well as internal features, By Geroge Bentham and J.D. Hooker, , , , Phylogenetic System of Classfication, , , Based on evolutionary relationships between the various organisms By, Hutchinson, , Numerical Taxonomy :, , , Carried out using computers, , , , Based on all observable characteristics, , , , Data processed after assigning number and codes to all the characters., , , Advantages : Each character gets equal importance and a number of, characters can be considered., , Cytotaxonomy :, , , Based on cytological informations., , , , Gives importance to chromosome number, structure and behaviour., Plant Kingdom, , 29
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Chemotaxonomy :, , , Based on Chemical constitutents of the plants., , Algae :, , , Chlorophyll bearing, simple, thalloid, autotrophic and largely aquatic, organisms., , Importance of Algae :, , , Help in carbon dioxide fixation by carrying out photosynthesis and have, immense economic importance., , , , At least half of the total carbon dioxide fixation on earth carried out by them., , , , Increases dissolved oxygen level in their environment., , , , Many species like Laminaria, Sargassum, Porphyra etc. are used as food., , , , , , , , , , Agar obtained from Gelidiumand Gracilaria which is used in ice-creams, and jellies and to grow microbes., Algin obtained from brown algae and carrageen from red algae used, commercially as hydrocolloids., Chlorella and Spirullina are unicellular algae, rich in protein and used even, by space travellers., Algae are unicellular like Chlamydomonas, colonial like Volvox or or, filamentous like spirogyra and Ulothrix. Occur in water, soil, wood moist, stones etc., , Algae are divided into 3 classes., (i) Chlorophyceae, , Green algae, Main pigment is chlorophyll ‘a’ and ‘b’., Cell wall has inner layer of cellulose and outer layer of pectose., , , , Has pyrenoids made up of starch and proteins., , Pigment and pyrenoids are located in Chloroplast., e.g., Chlamydomonas, Volvax, Spirogyra, Ulothrix, Chara., (ii) Phaeophyceae, Brown algae are brown coloured due to main pigments chlorophyll ‘a’,, , , 30, , Biology Class - 11
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‘c’ and fucoxanthin (xanthophyll), , Cell wall has cellulose with gelantionous coating of algin., Has mannitol and laminarin (complex carbohydrate) as reserve food, , material., , , Body divisible into holdfast, stipe and frond., , e.g., Ectocarpus, Fucus, Laminaria, Dictyota, Sargassum, (iii) Rhodophyceae, Red algae are red coloured due to pigments chlorophyll ‘a’, ‘d’ and, , r-phycoerythrin., , , Found on surface as well great depths in oceans., , Cell wall has cellulose., Reserve food material is floridean starch., , , e.g., Polysiphonia, Porphyra, Gelidium,Gracilaria., , Reproduction in Algae, Vegetative reproduction : by fragmentation, Asexual Reproduction : Flagellated zoospores in Chlorophyceae,, Biflagellated zoospores in Phaeophycease, By non-motile spores in Rhodophyceae., Sexual Reproduction : Isogamous, anisogamous or oogamous in, chlorophyceae and Phaeophyceae., By non-motile gametes and oogamous in Rhodophyceae., , Bryophytes :, , , ‘Amphibians of plant kingdom’., , , , Occur in damp, humid and shaded places., , , , Lack true roots, stem or leaves., , , , Main plant body is haploid and thallus like (prostrate or erect), , , , Economic Importance : Food for herbaceous animals., , Sphagnum in from of peat is used as fuel and also used as packing material, for trans-shipment of living material, as it has water holding capacity., Plant Kingdom, , 31
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Prevents soil erosion, alongwith lichens are first colonizers on barren rock., , , Is divided into two classes Liverworts (thalloid body, dorsiventral, e.g.,, Marchantia) and Mosses (have two stages in gametophyte–creeping, green,, branched, filamentous protonema stage and the leafy stage having spirally, arranged leaves e.g., Funaria, Polytrichum and Sphagnum)., , Reproduction in Bryophytes, , , Vegetative reproduction by fragmentation., , , , Asexual reproduction by gemmae formed in gemma cups., , , , Sexual reproduction : Main plant body is haploid, produces gametes and so, called Gametophyte. By fusion of antherozoids produced in antheridium, and egg cell produced in archegonium, results in formation of zygote which, develops into sporophytic structure differentiated into foot, seta and capsule., Spores produced in a capsule germinate to from free-living gametophyt e, (Protonema). Sporophyte is not free living but attached to photosynthetic, gametophyte from which derives nutrition., , Pteridophytes :, , , First terrestrial plants., , , , Prefer cool, damp and shady places to grow., , , , Grown as ornamentals., , , , Used for medicinal purpose, as soil binder., , , , , , , , , , , , 32, , Main plant body is sporophyte which is differentiated into true root, stem, and leaves., Leaves may be small as in Selaginella or large as in ferms., Sporangia having spores are subtended by leaf-like appendages called, sporophylls. (Sporphylls may be arranged to form strobili or cones.), In Sporangia, the spore mother cells give to spores after meiosis., Spores germinate to form haploid gametophytic structure called prothallus, which is free living, small, unicellular and photosynthetic., Prothallus bears antheridia and archegonia which bear antherozoids and, egg cell respectively which on fertilisation from zygote. Zygote produces, Biology Class - 11
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multicellular, well differentiated sporophyte., , , The four classes are : Psilopsida (Psilotum), Lycopsida (Selaginella),, Sphenopsida (Equisetum) and Pteropsida (Pteris)., , Heterospory : Two kinds of spores i.e., large (macro) and small (micro), spores are produced. e.g.,Selaginella and Salvinia., Seed Habit : The development of zygote into young embryos takes place, within the female gametophyte which is retained on parent sporophyte. This event, is precursor to seed habit and this is an important step in evolution and is found, Selaginella and Salvinia among the pteridophytes., , Gymnosperms :, , , , , , , , , , , , , , , , , , , Have naked seeds as the ovules are not enclosed by any ovary wall and, remain exposed., Includes shrubs and trees (medium and tall sized)., Have generally tap roots, stem may be unbranched (Cycas) or branched, (Pinus, Cedrus), leaves–needle like (Pinus) and pinnate (Cycas)., Roots of Pinus have fungal association in the form of mycorrhiza., Cycas have small specialized roots called coralloid root which are associated, with N2 fixing cyanobacteria., Heterosporous–Produce haploid microspores and megaspores., Male cone has microsporophylls which bear microsporangia having, microspores which develop into reduced gametophyte called pollengrain., Female cone has megasporophylls which bear megasporongia having, megaspores which are enclosed within the megasporangium (Nucellus)., One megaspore develops into female gametophyte bearing two or more, archegonia., Pollen grains carried in air currents reach ovules, form pollen tube which, reach archegonia and release male gametes which fertilise egg cell and form, zygote which produce embryos. Ovules develop into seeds which are not, covered., , Plant Kingdom, , 33
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Angiosperms :, , , , , Called flowering plants and have seeds enclosed in fruits., Divided into two classes–Dicotyledons (have two cotyledons) and, Monocotyledons (have one cotyledon)., , , , Smallest angiosperm : Wolfia, , , , Large tree : Eucalyptus (Over 100 meters), , , , , , , , , , , , Stamen has filament and anther. Anthers bear pollen grains. Pollen grains, have two male gametes., Pistil has stigma, style and ovary. Ovary has ovule in which female gametophyt, e (embryo sac) develops., Embryo sac has 7 cells and 8 nuclei.One egg cell 2 synergids, 3 antipodals, and two polar nuclei which fuse to form secondary nucleus., Pollen grain is carried by wind, water, insects and other agents reaches to, stigma and produces pollen tube which enters embryo sac., Double fertilisation : One male gemate fuses with egg cell (Syngamy) to, form zygote which develops into embryo., , Other male gamete fuses with secondary nucleus (triple fusion) which forms, triploid primary endosperm nucleus (PEN). PEN develops into endosperm which, nourishes the developing embryo., , , Ovules develop into seeds and ovaries into fruits., , Questions, , Very Short Answer Question, , (1 mark each), , 1. What is a pyrenoid body ?, 2. Define gemma., 3. Which group of plants is regarded as first terrestrial plants ? Why ?, 4. Which organism is regarded as one of the tallest tree species ?, 5. The gametes and spores of phaeophyceae have a distinct morphology. Give, its name., 34, , Biology Class - 11
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6. Which substance has structural similarity to floridean starch ?, 7. Name the organism which exhibit heterospory and seed habit., , Short Answer Question-I, , (2 marks each), , 8. Sphagnum has a lot of economic importance. Justify., 9. Gymnosperms can show polyembryony. Why do you think so ?, 10. How is leafy stage formed in mosses ? How is it different from, protonema ?, , Short Answer Question-II , , (3 marks each), , 11. The leaves in gymnosperms are adapted to withstand xerophytic conditions., Justify., 12. The gametophytes of bryophytes and pteridophytes are different from that, of gymnosperms. How ?, 13. Roots in some gymnosperms have fungal or algal association. Give examples,, their names and role in the plants., 14. Why is presence of water a must for fertilisation in pteridophytes ?, , Long Answer Questions , , (5 marks each), , 15. Draw the life cycle of an angiosperm alongwith a brief note on double, fertilisation., 16. Explain alternation of generation in plants., , Answers, , Very Short Answers , , (1 mark each), , 1. Proteinaceous body usually surrounded by starch found in algae., 2. Gemma are green, multicullular, asexual buds which develop in receptacles, called as gemma cups., 3. Pteriodphytes. As they possess vascular tissues–xylem and phloem., 4. Sequoia, 5. Pyriform (pear-shaped), bear two laterally attached flagella., Plant Kingdom, , 35
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6. Amylopectin and glycogen., 7. Selaginella and Salvinia., , Short Answers-I , , (2 marks each), , 8. Provide peat used as fuel : used as packing material for trans-shipment of, living material., 9. Have two or more archegonia, so polyembryony can occur., 10. Leafy stage develops from secondary protonema as a lateral bud. Protonema, is creeping, green, branched frequently filamentous stage whereas leafy stage, is upright with spirally arranged leaves., , Short Answers-II (3 marks each), 11. Gymnosperms like conifers have : needle shaped leaves to reduce surface, area, thick cuticle and sunken stomata to reduce water loss., 12. Male and female gametophyte have free existence in bryophytes and, pteridophytes but not in Gymnosperms. They remain within sporangia, retained on sporophytes., 13. Pinus has fungal association to form mycorrhiza which helps in absorption, of water and minerals. Cycas has algal association in coralloid roots which, are associated with N2 fixing cyanobacteria., 14. The antheridia produces male gametes, antherozoids which swim in water, to reach archegonia, bearing non-motile egg. Thus fertilisation can occur, only when water is present in the surrounding medium., , Long Answers (5 mark each), 15. Refer Figure 3.6, page no. 41, NCERT, Text Book of Biology for Class XI., 16. Refer ‘Points to Remember’ and Page No. 42,NCERT, Text book of Biology, for class XI., , , 36, , Biology Class - 11
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Point to Remember, Basis of Classification :, , Animals are classified on the basis of following few fundamental features—, 1. Levels of Organisation :, , (1) Cellular level : Cells are arranged as loose cell aggregates, e.g.,sponges., (2) Tissue level : The cells performing the same function are arranged into, tissues, e.g., Coelenterates., (3) Organ level : Tissues are grouped together to form organs, each, specialised for a particular function. e.g., platyhelminthes., (4) Organ system level : organs are associated to form functional systems, e.g., Annelids, Arthropods, Molluscs, Echinoderms and Chordates., Example : Circulatory System., , Open type : Blood pumped out through heart. Not confined to blood vessels., Cells and tissues are directly bathed in it., , Closed types : Blood is circulated through blood vessels (arteries,veins and, capillaries), 2. Symmetry :, Asymmetrical : Cannot be divided into equal halves through median plane, , e.g., Sponges., Radial symmetry : Any plane passing through central axis can divide organism, , into identical halves. e.g., coelentrates,Ctenophores and echinoderms., Bilateral symmetry : Only one plane can divide the organism into two identical, , left and right halves e.g., Annelids and Arthropods., 3. Germinal Layers :, Diploblastic : Cells arranged in two embryonic layers i.e., external ectoderm, and internal endoderm. (Mesoglea may be present in between ectoderm and, endoderm) e.g., porifers and Coelentrates. (Cnidarians), , Triploblastic : Three layers present in developing embryo i.e., ectoderm,, mesoderm and endoderm. e.g., Platyhelminthes to Chordates., Animal Kingdom, , 37
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4. Coelom (Body cavity which is lined by mesoderm), , Coelomates : Have coelom e.g., Annelids, Arthropods, molluscs, Echinoderms,, Chordates etc., , Pseudocoelomates : No true coelem as mesoderm is present in scattered, pouches between ectoderm and endoderm. e.,g., Aschelminthes., , Acoelomates : Body cavity is absent e.g., Platyhelminthes., 5. Segmentation (A) True Metamerism : Found Annelida,Arthropoda,, Chordata :, Segmentation is external as well as a internal in Annelids., , Segmentation is external in Arthropods., Segmentation is internal in chordates., , Metamerism : If body is externally and internally divided into segments, , (metameres) with serial repetition of atleast some organs, then phenomenon is, called metamerism e.g., Earthworm. (B) Pseudometamerism : Found in, tapeworm. The proglottids (segments of tapeworm) budded off from neck, not embryonic in origin., 6. Notochord :, Rod-like structure formed during embryonic development on t he dorsal side., , It is mesodermally derived e.g., Chordates., Non-chordates do not have notochord .e.g., porifera to echinoderms., , , Phylum Porifera :, , , , , , , , , , , Also called sponges., Are usually marine and asymmetrical., Have cellular level of organisation and diploblastic animals., Food gathering, respiratory exchange and removal of wastes occurs through, water canal system. Digestion intracellular., Ostia (minute pores on body), spongocoel (body cavity) and osculum help, in water transport. They are lined by choanocytes (collar cells)., Body wall has skeleton of spicules or spongin fibres., Animals are hermaphrodite. Fertilisation internal. Development is indirect, (i.e., has a larval stage distinct from adult stage) e.g., Sycon, Euspongia., Spongilla (Fresh water sponge), , Phylum Coelenterata :, , , , , 38, , Also called Cnidarians., Are usually marine and radially symmetrical., Sessile or free swimming., Biology Class - 11
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, , , , , , , , , , , , , , , Have tissue level of organisation., Are diploblastic (with mesogloea), Capture of prey, anchorage and defence occurs through cnidoblasts/cnidocytes, (have stinging capsules nematocytes) present on tentacles., Digestion extracellular and intracellular., Have a central gastro-vascular cavity and an opening, hypostome., Body wall of some composed of calcium carbonate. e.g. corals., exhibit two body forms : polyp and medusa e.g., Hydra, Aurelia., Alternation of generation between body forms called metagenesis ocurs in, Obelia where :, Polyp. (Sessile and cylindrical), Medusa, (free swimming &, umbrella shaped), e.g., Physalia, Adamsia, Pennatula, Gorgonia,Meandrina., , Phylum Ctenophora :, , , Also called as sea walnuts or comb jellies., , , , Are exclusively marine, radially symmetrical., , , , Have tissue level organisation, are diploblastic., , , , Digestion both extra and intracellular., , , , Body has eight external rows of ciliated comb plates for locomotion., , , , Show Bioluminescence (Property of living organisms to emit light)., , , , Hermaphrodite (sexes are not separate)., , , , Only sexual reproduction occurs. Exernal fertilization. Indirect development., e.g., Ctenoplana, Pleurobrachia., , Phylum Plathyhelminthes :, , , , , , , , , Also called as ‘flat worms’., Have dorsoventrally flattened body. Are mostly endoparasites in animals., Are bilaterally symmetrical, triploblastic, acoelomate,with organ level of, orgnisation., Absorb nutrients through body surface., Parasitic forms have hooks and suckers., ‘Flame cells’ help in osmoregulation and excretion., Animal Kingdom, , 39
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, , , Sexes not separate., Fertilisation internal. Many larval stages present. Planaria has high, regeneration capacity. e.g., Taenia, Fasciola., , Phylum Aschelminthes :, , , , , , , , , , Also called ‘round worms’., May be free living, parasitic, aquatic or terrestrial., Are bilaterally symmetrical, triploblastic, pseudocoelomate., Alimentary canal complete (has muscular pharynx), wastes removed through, excretory pore., Sexes separate. (dioecious), Females longer than males., Fertilisation internal. Development direct or indirect. e.g., Ascaris,Wuchereria,, Ancylostoma., , Phyum Annelida :, , , , , , , , , , , , , , , Are aquatic or terrestrial, free-living or parasitic., Are bilaterally symmetrical, triploblastic, organ-system level of organisation, and metamerically segmented body., Are coelomate animals., Have longitudinal and circular muscles for locomation., Have closed circulatory system., Nereis (dioecious and aquatic annelid) has lateral appendages called parapodia, for swimming., Have nephridia for osmoregulation and excretion., Neural system consists of paired gangila connected by lateral nerves to a, double ventral nerve cord., Reproduction is sexual., e.g., Earthworm (Pheretima) and Leech (Hirudinaria) which are hermaph, rodites (i.e., monoecious)., , Phylum Arthropoda :, , , , , , 40, , Largest phylum of Animalia., Are bilaterally symmetrical, triplobastic, segmented externally and organ, system level of organisation, coelomate., Body divisible into head, thorax, abdomen and has a chitinous exoskeleton., Jointed appendages are present., Biology Class - 11
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Respiration by gills, book gills, book lungs or tracheal system. Excretion, through malpighian tubules., Sensory organs : Antennae, eyes; Organs of balance : Statocysts., Fertilisation usaully internal. Development is indirect or direct. Are mostly, oviparous., , e.g., Apis, Bombyx, Laccifer, Anopheles, Culex, Aedes, Locusta, Limulus., , , Phulum Mollusca :, Second largest phylum of Animalia., Terrestrial or aquatic, Are bilaterally symmetrical, triplobastic and organ system level of organisation,, coelomate., Body vidisble into head, muscular foot and visceral hump and is covered, by calcareous shell and is unsegmented., Mantle : Soft and spongy layer of skin; Mantle cavity : Space between, visceral hump and mantle., Respiration and excretion by feather like gills in mantle cavity., Head has sensory tentacles. Radula a rasping organ for feeding in mouth., Are oviparous, dioecious, have indirect development., , e.g., Plia, Pinctada, Octopus, Sepia, Loligo, Aplysia, Dentalium, Chaetopleura., , , Phylum Echinodermata :, , , , , , , , , , , , Are spiny bodied organisms with endoskeleton of calcareous ossicles., Are exclusively marine, radially symmetrical in adult but bilaterally, symmetrical in larval stage. Organ system level of organisation., Triploblastic and coelomate., Digestive system complete. Mouth ventral, Anus on dorsal side., Food gathering, respiration, locomotion carried out by water vascular system., Excretory system is absent., Reproduction–sexual, sexes are separate., Fertilisation external. Development indirect (free swimming larva), e.g., Asterias, Cucumaria, Antedon, Echinus, ophiura., , Phyum Hemichordata :, , , , Represents small group of worm-like organisms., Was earlier placed as sub-phylum of Phyum Chordata., Animal Kingdom, , 41
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Bilaterally symmetrical, triploblastic and coelomate with organ system level, of organisation., Body cylindrical, has proboscis, collar and trunk., Circulatory System–open., Respiration by gills, excretion by proboscis gland., Sexes separate, external fertiliastion, indrect development., , e.g, Balanoglossus, saccoglossus., , , Phylum Chordata :, , , Presence of Notochord., , Have dorsal hollow nerve chord., , , Have paired pharyngeal gill slits., , , Bilaterally symmetrical, triploblastic, coelomate, organ system level of, , organisation., , Heart is ventral., , , Post anal tail present, closed circulatory system., , , (i) Sub-Phyla Urochordata /Tunicata, Notocohord present only in larval tail., e.g., Ascidia, Salpa, Doliolum, , , (ii) Sub-phyla Cephalochordata, , , , , Notochord extends from head to tail (Persistent), e.g., Amphioxus., , (iii) Sub-Phyla Vertebrata, Have notochord only during embryonic period., , Notochord gets replaced by bony or cartilaginous vertebral column., , , Have ventral muscular heart, kidneys for excretion and osmoregulation, paired, , appendages (fins or limbs), , , Vertebrata have two Division :, (a) Agnatha (Lacks Jaw) : Class : Cyclostomata, , Live as ectoparasites on some fishes., , Have sucking and circular mouth without jaws., , Have 6-15 paris of gill slits for respiration., , No scales, no paired fins., , Cranium and vertebral column is cartilagenous., 42, , Biology Class - 11
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Marine, Migrate to fresh water for spawning and die after spawning., , Larva returns to ocean after metamorphosis., e.g., Petromyzon, Myxine, (b) Gnathostomata (Bear Jaws)–divides into two super classes :, , Super-class : Pisces, 1. Class : Chondrichthyes :, , Have cartilagenous endoskeleton, are marine with streamlined body., , Mouth ventral., , Gill slits without operculum (gill cover)., , Skin has placoid scales; jaws–very powerful., No air bladder, so swim constantly to avoid sinking., , Teeth are backwardly directed, modified placoid scales., , Notochord is persistent throughout life., , Two chambered heart; poikilotherms (cold-blooded), , Sexes separate; males have claspers on pelvic fins., , Internal fertilisation; viviparous., , e.g., Tarpedo, Trygon, Scoliodon, Pristis, Carcharodon, 2. Class : Osteichthyes, Have bony endoskeleton, Aquatic, Mouth is usually terminal. Body-Streamlined, , Four pairs of gill slits covered by operculum, heart two chambered, cold, , blooded., Sking has cycloid/ctenoid scales., , Have air bladder which regulates buoyancy., , Sexes separate., , Usually oviparous, fertilisation external., , Development direct., , e.g., Hippocampus, Labeo, Catia, Betla, Clarias, Exocoetus, , , Sub-Phylum Vertebrata : Gnathostomata, Super Class : Tetrapoda, 1. Class : Amphibia, Can live in aquatic as well as terrestrial habitats., Body divisible into head and trunk, paired limbs., , Animal Kingdom, , 43
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Skin moist. No scales., Tympanum represents ear. Eyes have eyelids., , Cloaca is the common chamber where alimentary canal, urinary and, , reproductive tracts open., Respiration by gills, lungs or skin., , Heart is 3-chambered; cold-blooded; Sexes separate; fertilisation external., , Oviparous. Indirect development., , e.g., Bufo, Rana, Hyla, Salamandra, Ichthyophis, , 2. Class : Reptilla, Creep or crawl to locomote. Mostly terrestrial., , Body has dry and cornified skin and epideremal scales or scutes., , Tympanum represents ear., , Limbs, when present, are two pairs, , Snakes and lizards shed, scales as skin cast., , Heart 3-chambered but 4-chambered in crocodiles., , Sexes Separate; fertilisation internal., , Oviparous. Direct development., , e.g., Testudo, Naja, Vipera, Calotes, Crocodilus, Hemidactylus, 3. Class : Aves, Presence of feathers except flightless birds and beak (modified jaws), without teeth., Forelimbs are modified into wings., , Hind limbs have scales, modified for walking, swimmng or clasping., , Skin is dry as no glands on skin except oil gland at base of tail., , Endoskeleton bony with air cavities (pneumatic) and hollow bones to, , assist in flight., Crop and Gizzard—Additional chamber in digestive tract., , Air sacs are connected to lungs to supplement respiration., , Warm blooded (homoiothermous), Heart–Four chambered., , Sexes separate, fertilization internal, , Oviparous. Direct development., e.g., Columba, Struthio, Pavo, Corvus, Neophron, Pstittacula Aptenodytes., , 4. Class : Mammalia, , Have mammary glands to nourish young ones., , , Have two pairs of limbs, adapted to perform special work., , , Skin has hairs., 44, , Biology Class - 11
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, External ears or, pinna present., , , Different types of teeth in jaw., , , Homoiothermous; Heart–Four chambered, Lungs for respiration., , , Sexes are separate, fertilisation internal., , , Viviparous. Direct development., , , e.g., Rattus, Canis, Elephas, Equus. Oviparous mammal is, Ornithorhynchus., , Questions, , Very Short Answer Questions , , (1 mark each), , 1. What is mesogloea ? Where is it found., 2. When is the development of an organism called as Indirect ?, 3. Why are corals important ?, 4. What is the difference between class Amphibia and class Reptilia in respect, of their skin ?, 5. Which phylum consists of organisms with cellular level of organisation ?, 6. Name the arthropod which is a (i) Living fossil, (ii) Gregarious pest., 7. Which organ helps in excretion in (i) Arthropods, (ii) Hemichordates ?, , Short Answer Questions-I , , (2 marks each), , 8. Distinguish between poikilothermous and homoiothermous organisms., 9. Define metagenesis with a suitable example., 10. List the characteristic features of class Mammalia., , Short Answer Questions-II , , (3 marks each), , 11. What is the difference between organisms on the basis of the coelom ? Give, examples for each., 12. Compare the water transport (vascular) system of poriferans and the, echinoderms., 13. What are the feature of class Aves which help them in flying ?, , Long Answer Questions , , (5 marks each), , 14. Distinguish between the chordates and non-chordates., 15. Differentiate between class Chondrichthyes and class Osteichthyes., Animal Kingdom, , 45
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Answers, , Very Short Answers , , (1 mark each), , 1. Undifferentiated layer present between ectoderm and endoderm. It is found, in Coelenterates., 2. Have a larval stage morphologically distinct from adult., 3. Have skeleton composed of calcium carbonatge which gets deposited and, can lead to formation of land forms, e.g., Lakshadweep (a coral island)., 4. Class Amphibia : Have moist skin without scales., , Class Reptilia : Have dry cornified skin with scales., 5. Phylum Porifera., 6. (i) Limulus (King crab), (ii) Locusta (Locust), 7. (i) Malpighian tubules, (ii) Proboscis gland., , Short Answers-I , , (2 marks each), , 8. Poikilothermous (cold blooded); Lack ability to regulate their body, temperature., , Homoiothermous (Warm) : Can regulate body temperature., 9. Refer ‘Points to Remember’., 10. Refer ‘Points to Remember’., , Short Answers-II , , (3 marks each), , 11. Refer ‘Points to Remember”., 12. Refer ‘Points to Remember, NCERT, Text Book of Biology for Class XI., 13. Wings, bones long and hollow with air cavities, air sacs connected to lungs, to supplement respiration., , Long Answers , , (5 marks each), , 14. Refer Table 4.1, page 55, NCERT, Text Book of Biology for Class XI., 15. Refer ‘Points to Remember’., , , 46, , Biology Class - 11
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Points to Remember, Morphology : The study of various external features, forms and relative, position of different organs of the organism is known as morphology. It may be, further divided into internal and external morphology., External Morphology : It deals with external forms like shape, size, colour,, structure and relative position of different organs., Internal Morphology : Further divided into anatomy and histology., Anatomy : It deals with the study of internal structure exposed after dissection, and opening of various parts of an organ., Histology : The study of tissues, their composition and structure., Adaptation : Any alteration in the structure or function of an organism, or any of its part that results from natural selection and by which the organism, becomes better fitted to survive and multiply in its environment., The Root : The root is underground part of the plant and develops from, elongation of radicle of the embryo., Characteristics : It is inside the soil, chlorophyll is absent, absence of nodes,, internodes, leaves and buds; positive geotropic and hydrotropic and negative, phototropic., Main functions of root system :, 1. Absorption of water and minerals from the soil., 2. Provides anchorage to plant parts., 3. Stores reserve food material and synthesises plant growth regulators, (cytokinins), Morphology of Flowering Plants, , 47
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Various types of root, ↓, Tap root, , Fibrous root Adventitious root, , ↓, , ↓, , ↓, , Originates from radical Originates from base of Originates from parts of, , the stem , the plant other than radicle, Dicotyledonous plants, Monocotyledonous, , Banyan tree (Prop roots), , e.g., gram, pea, mango, plants, e.g., wheat,, , Maize (stilt roots), , mustard. , , Rhizophora (Respiratory, , paddy, grasses., , , , roots), , Regions of Roots, Root Cap : The root is covered at the apex by the thimble-like structure, which protect the tender apical part., Region of meristematic activity : Cells of this region have the capability, to divide; cells are small, thin walled with dense protoplasm., Region of elongation : Cell of this region are elongated and enlarged.This, region is responsible for the growth of root in length., Region of Maturation : This region has differnentiated and matured cells., Some epidermal cells form very fine and delicate thread like structures called, root hairs., Modifications of Root : Roots are modified for support, storage of food,, respiration., , , For support : Prop roots in banyan tree, stilt roots in maize and sugarcane., , , , For respiration : Pneumatophores in Rhizophora (Mangrove)., , , , For storage of food : Fusiform (radish), Napiform (turnip), Conical (carrot),, Fasiculated fleshy roots (Asparagus)., , The Stem : Stem is the aerial part of the plant and develops from plumule, of the embryo. It bears nodes and internodes., Functions of stem : Exposure of leaves, conduction of water and minerals,, translocation of food, exposure of flowers and fruits., 48, , Biology Class - 11
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Modifications of Stem :, In some plants the stems are modified to perform the function of storage of, food, support, protection and vegetative propagation., , , , , , , , , , For food storage : Rhizome (ginger, turmeric), Tuber (potato), Bulb (onion),, Corm (Colocasia, Amorphophallus/Zamin-kand), For support : Stem tendrils of watermelon, grapevine, cucumber, pumpkins., For protection : Axilliary buds of stem of Citrus, Bougainvillea get modified, into pointed thorns. They protect the plants from animals., For vegetative propagation : Underground stems of grass (runner), strawberry, (stolons), leateral branches of mint and jasmine, Eichhornia (offsets)., For assimilation of food : Flattened stem of Opuntia and cylindrical stem, of Euphorbia contains chlorophyll and performs photosynthesis., , The Leaf : Develops from shoot apcial meristem, flattened, green structure, acropetally arranged manufacture the food by photosynthesis. It has bud in axil., A typical leaf has leaf base, petiole and lamina (leaf blade). In some leguminous, plants the leaf base may become swollen which is called as pulvinus., Leaf base → bears two lateral outgrowth called stipules, Expanded to enclose stem, , Swollen, Pulvinus, , Sheathing leaf base , Covers stem totally, (Gram, wheat), , Partially, (Butter cup), , Mimosa, (Leguminous plant), , Types of Leaf, Simple , (Single leaf blade) , e.g., mango, peeple, Pinnately, Compound, (Leaflets present on common,, axis rachis), (Neem, rose), , Compound, (Leaf has number of leaflets), Palmately, Compound, (Leaflets attached to common, point at petiole tip), (Silk, cotton), , Morphology of Flowering Plants, , 49
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Venation : The arrangement of veins and veinlets in the lamina of leaf., Types of Venation :, 1. Reticulate : Veinlets form a network as in leaves of dicotyledonous plants, (China rose, peepal)., 2. Parallel : Veins are parallel to each other as in leaves of monocotyledonous, plants (grass, maize,sugarcane)., , Phyllotaxy : The pattern of arrangement of leaves on the stem or branch., Types of phyllotaxy, Alternate, , Opposite, , Whorled, , (Single leaf at a node)in, alternate manner, e.g., China rose Mustard,, , (Two leaves at a node) in, opposite manner, e.g., Calotropis, guava, , (More than two leaves in a, whorl at a node), e.g., Nerium, Alstonia, , Functions of Leaf, photosynthesis, gaseous exchange, transpiration, protection of buds and, conduction., , 50, , Biology Class - 11
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Modifications of Leaves :, Type Function Example, Tendrils, Spines, Pitcher, Hook, Fleshy Leaves, , , :, :, :, :, :, , (Climbing), (Protection), (Nutrition), (Support), (Storaged food), , —, —, —, —, —, , Sweet Pea, Pea, Aloe, Opuntia, Argemone, Nepenthes, Cat’s nail, Onion and Garlic, , Inflorescene : The arrangement of flowers on the floral axis (Peduncle), Main types of Inflorescence, , , Main types of Inflorescence, , Recemose, 1., 2., , , , Cymose, , It is indefinite inflorescene, 1., Main axis continues to grow and, 2., flowers borne in acropetal succession , e.g. : Radish, Mustard, Amaranthus , , It is definite inflorescence, Main axis terminates in flowers and the, flowers borne in basipetal succession, e.g. : Cotton, Jasmine, Calotropis, , Special Inflorescence type—Ficus, Salvia, Euphorbia,Sunflower, Flower—Modified shoot meant for reproduction, On the basis of symmetry flower can be :, ↓, , ↓, , ↓, , Actinomorphic, , Zygomorphic, , Asymmetric, , (Radial symmetry), , (Bilateral symmetry), , (Irregular), , ↓, , ↓, , ↓, , Flower can be divided, , Flower can be divided into Flower cannot be divided, , into two equal halves, , two similar halves only in in two similar halves by, , in any radial plane, , one plane, , passing through centre , , any vertical plane passing, through centre, , eg : Mustard, Datura,, , eg : Pea, bean, Gulmohar, eg : Canna, , Chilli, , cassia, Morphology of Flowering Plants, , 51
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On the basis of floral appendages flower can be :, ↓, ↓, ↓, Trimerous, Tetramerous, Pentamerous, (multiples of 3), (multiples of 4), (multiples of 5), On the basis of position of Calyx, corolla and androecium in respect of ovary,, flower can be—, of position of Calyx, corolla and androecium, ↓, Hypogynous, (Superior Ovary), , ↓, Perigynous, (Half inferior ovary), , ↓, Epigynous, (inferior ovary), , ↓, ↓, ↓, Mustard, China rose,, Plum, Rose, Peach, Guava, Cucumber, Brinjal, Plum, Rose, Peach, ray florets (sun flower), Thalamus/Receptacle : Swollen end of flower stalk (pedicel) which bears four, whorls of flower viz., Calyx (K), Corolla (C), Androecium (A) and Gynoecium (G)., , Flower can be, Bisexual , Unisexual, if have both Androecium , can, and Gynoecium, have only, have only Gynoecium, Androecium/Stamen, Carpel, 52, , Biology Class - 11
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Bract—Reduced leaf base found at the base of pedicel. Flowers with bracts, are called bracteale and without bracts are called ebracteate., Perianth : If calyx and corolla are not distinguishable, they are called, perianth., Example : Lily, Aestivation: The mode of arrangement of sepals or petals infloral bud., , Types of aestivation :, 1. Valvate : Sepals or petals just touch one another at the margin, withut, overlapping. e.g., Calotropis, 2. Twisted : Sepals or petals overlap the next sepal or petal e.g., China rose,, Cotton, lady’s finger., 3. Imbricate : The margins of sepals or petals overlap one another but not in, any definite direction, e.g., Cassia, Gulmohar., 4. Vexillary : The largest petal overlaps the two lateral petals which in turn, overlap two smallest anterior petals, e.g., Bean, Pea., Placentation : The arrangement of ovules within the ovary., , Types of Placentation :, 1. Marginal : Placenta forms a ridge along the ventral suture of ovary, e.g.,, Pea., 2. Axile : Margins of carpels fuse to form central axis, e.g., China rose, Tomato,, Lemon, 3. Perietal : Ovules develop on inner wall of ovary, e.g., Mustard, Argemone, 4. Free central : Ovules borne on central axis, lacking septa, e.g., Dianthus,, Primrose, , 5. Basal : Placenta develop at the base of ovary, e.g., Sunflower, Marigold, Morphology of Flowering Plants, , 53
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Embryonal axis—Radicle and plumule., Endospermous seed—endosperm present in mature seed. eg. castor, Non-endospermous seed—endosperm not present in mature seeds, eg. bean,, , Questions, Very Short Answer Question, , (1 mark each), , 1. Which part of Opuntia is modified to form spines ?, 2. Name one plant in which leaf is pinnately compound., 3. In mangroves, pneumatophores are the modified adventitious roots. How, are these roots helpful to the plant ?, 4. Which part in Ginger and Onion are edible ?, 5. Why do various plants have different type of phyllotaxy ?, 6. State the main function of leaf tendril., 7. Which plant family represent the following floral formula :, , 8. The endosperm is formed as a result of double fertilisation (triple fusion)., What is its function ?, 9. Which type of venation do you observe in dicot leaf ?, 10. In pea flower, the aestivation in corolla is known as vexillary. Give reason., 11. What is the name given to the cotyledon in case of Monocots., 12. Name the part modified for food storage in the following (a) carrot (b) Radish, (c) Potato (d) Dahlia (e) Turmeric (f) Sweet potato, , Short Answer Questions-I , , (2 marks each), , 13. Flower is a modified shoot Justify., 14. Name the type of root of the following :, (a) Roots performing the function of photosynthesis., (b) Roots come above the surface of the soil to absorb air., (c) The pillar like roots developed from lateral branches for providing, mechanical support., (d) Roots coming out of the lower nodes of the stem and provide the support, to the plant., 15. Identify the type of tendrils found in the following plants—, (a) Cucumber (b) Pea (c) Grape vines (d) Water Melon, 16. Fill up the blank spaces (a), (b), (c) and (d) in the table given below :, Morphology of Flowering Plants, , 55
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17., , , , , 18., , Provide the scientific terms for the following :, (i) The leaf without a petiole (stalk)., (ii) The flat and expanded portion of a leaf., (iii) Orderly arrangement of leaves on the node., (iv) Lateral appendages on either side of the leaf., Differentiate between peduncle and Pedicel, , Short Answer Question-II , , (3 marks each), , 19. Observe the given figure showing various types of placentration. Identify, the type of placentation. Give one example of each., , 20. ‘Potato is a stem and sweet potato is a root.’ Justify the statement on the, basis of external features., 21. Define aestivation. Which type of aestivation is found in China rose, Calotropis, Gulmohar and Pea., 22. Give two example of each type of phyllotaxy., 23. Differentiate between :, (a) Actinomorphic flower and Zygomorphic flower, (b) Apocarpous ovary and Syncarpous ovary, (c) Racemose inflorescence and Cymose inflorescence, 24. In the given structure of a Monocotyledonous seed label the parts a, b, c, d,, e. Give the function of part ‘a’., 56, , Biology Class - 11
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25. Maize grain usually called as a fruit and not a seed. Why ?, , Long Answer Questions (5 marks each), 26. Describe various stem modifications associated with food storage, climbing, and protection., , Answers, , Very Short Answers , 1., 2., 3., 4., , (1 mark each), , Leaves, Neem, Rose’, Acacia., Pneumatophores is mangroves help in respiration., Ginger–Rhizome and Onion–bulb, , 5. For proper exposure of leaves to get sunlight., 6. The leaf tendrils help the plant for climbing., 7. Lilliaceae, 8. Endosperm stores the food., 9. Reticulate venation., 10. In peas, there are five petals. The largest one (standard) overlaps the two, lateral petals (wings) which in turn overlap the two smallest anterior petals, (keel)., 11. Scutellum., 12. (a) and , , (b) Fleshy tap root, , (e) Rhizome, , (f) Fleshy root tuber, , (c) Stem tuber , , (d) root tuber, , Morphology of Flowering Plants, , 57
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Short Answers-I, , (2 marks each), , 13. The flower is considered to be a modified shoot because the internodes, in flower are highly condensed and the appendages such as sepals, petals,, stamens and carpels(pistil) are generally large in number., 14. (a) Assimilatory roots, (b) Respiratory roots, (c) Prop roots, (d) Stilt roots, 15. (a) Stem tendril, (b) leaf tendril, (c) and, (d) both stem tendrils, 16. (a) Floral parts are situated below the ovary., (b) Half inferior, (c) Epigynous, (d) Floral parts are situated above the ovary., 17. (i) Sessile, (ii) Lamina, (iii) Phyllotaxy, (iv) Stipules, , Short Answers-I, , (3 marks each), , 18. Penduncle is the axis of inflorescence which generally bears a number of, flowers., , Pedicel is the stalk of the flower which bears a single flower., , Short Answers SA-II , , (3 marks each), , 19. (a) Marginal placentation —, , Pea, , (b) Parietal placentation , , —, , Mustard, Argemone, , (c) Free central plancentation , , —, , Dianthus, Primrose, , 20. Potato is the swollen tip of an underground stem branch (stolon). It has, nodes (eyes) which consist of one or more buds subtended by a leaf scar., Adventitious roots also arise during sprouting. On the other hand sweet potato, is a swollen adventitious root (tuberous root). It has no nodes, internodes, and buds like a stem., 21. The mode of arrangement of sepals or petals in a floral bud is known as, aestivation., China rose – twisted Calotropis – valvate, Gulmohar – imbricate Pea – vexillary, 58, , Biology Class - 11
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22. Type of phyllotaxy, , Examples, , , (i) Alternate, , China rose, mustard, , (ii) Opposite, , Calotropis, guava, , (iii) Whorled, , Nerium, Aistonia, , 23. (a) Actinomorphic Flower, , Zygomorphic flower, , , , (1) Two equal havles are produ-, , (1), , Two equal halves are formed, , , , by any vertical division passing , , ced only by one vertical, , , , through the centre. , , division, , , , It has a radial symmetry., , (2), , (2) It has a bilateral symmetry., , , (b) Apocarpous Ovary, , Syncarpous Ovary, , , , (1) The flower has fused carpels., , (1), , The flower has several free, , , , free carpels (ovary)., , , , On maturity it forms fruitlet, , (2), , , , (2) On maturity it forms a single, , of aggregate type. , , fruit., , , (c) Racemose inflorescence, , Cymose inflorescence, , , , (1) The main axis has a limited, , (1), , The main axis has unlimited, , , , growth. , , , , Flowers are arranged, , (2) Flowers are arranged, , , , acropetally i.e., the lower, , basipetally i.e., the lower, , , , flower are younger , , (2), , growth., , flowers are older, , 24. (a) Endosperm, (b) Scutellum, (c) Coleoptile, (d) Coleorrhiza, (e) Aleurone layer, Function of (a)—Provide nutrition., 25. Maize grain is a single seeded fruit in which the seed covering or testa is, fused with pericarp or fruit wall. A micropyle is not found but base of style, is present., Morphology of Flowering Plants, , 59
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Long Answers , , (5 marks each), , 26. Stem Modification :, , For food storage : Ginger (Rhizome), Potato (Tuber), Onion (Bulb),, , Colocasia (Corm)., , For climbing (support) : Sterm tendril (cucumber,grapevine,watermelon), , , For protection : Thorn (Bougainvillea, Citrus, Duranta) Description :, , Refer page 68, NCERT, Text Book of Biology for Class XI., , , 60, , Biology Class - 11
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Points to Remember, Anatomy : Anatomy is the study of internal structure of organisms. Plant, anatomy includes organisation and structure of tissues., Tissue is a group is cells having a common origin and usually performing, a common function., There are two types of tissues (i) Meristematic (ii) Permanent, Meristematic tissues : The meristematic tissue is made up of the cells which, have the capability to divide. Meristems in plants are restricted to a specialised, regions and responsible to the growth of plants., Meristems, Apical meristem, , Intercalary meristem, , Lateral Meristem, , Occurs at the tips of, Occurs between, Occurs in the mature, roots and shoots mature tissue region of roots and, shoots, , Primary meristem, Primary meristem, Secondary meristem, , Increase the length of, Occur in grasses and, Appears later than, plant regenerate parts primary meristem, removed by grazers and responsible for, secondary growth, Axillary bud : The buds which are present in the axils of leaves (Consist, of cells left behind from shoot apical meristem) and are responsible for forming, branches of flowers., Permanent tissues : The permanent tissues are derived from meristematic, tissue, are composed of cells, which have lost the ability to divide and have become, structurally and functionally specialised., , , Anatomy of Flowering Plants, , 61
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Types of Permanent Tissue, , Simple (i) , Parenchyma, , Collenchyma, , Scierenchyma, , Complex (ii), Xylem, , Phloem, , Parenchyma : Living, thin walled isodiametric cells, with interceullar spaces,, cell wall is made up of cellulose. It performs the functions like photosynthesis,, storage, secretion., Collenchyma : It is formed of living, closely packed cells. Its cells are, thicknened at the corners due to depositon of celluose and pectin. It provide, mechanical support to the growing parts of the plant. It is either found in, homogenous layer or patches., Sclerenchyma : It is formed of dead cells with thick and lignified walls., Provide mechanical support to organs. They have two types of cells : fibres and, sclereids., (a) Fibers—are thick walled,elongated and pointed cells., (b) Sclereids—are spherical, oval or cylindrical, highly thickened dead cells, with narrow lumen. Found in walls of nut, pulp of fruits like guava, seed coat of, legumes and leaves of tea., Xylem : Xylem consists of tracheids vessels, xylem fibres and xylem, parenchyma. It conducts water and minerals from roots to other parts of plant., (a) Tracheids—Tube like cells with thick and lignified walls and tapering, ends; dead, without protoplasm., (b) Vessel—long cylindrical structure made up of many cells with large, central cavity, devoid of protoplasm. Present in angiosperms., (c) Xylem fibres—highly thickened walls; with obliterated lumens; septate, or aseptate., (d) Xylem parenchyma—living and thin walled; cell walls made up, cellulose, store food material in form of starch or fat., Radial conduction of water takes place by ray parenchymatous cells, Protoxylem : The first formed primary xylem elements., Metaxylem : The later formed primary xylem., Endarch : Protoxylem lies towards the centre and metaxylem towards the, periphery of the organ; in stem, 62, , Biology Class - 11
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Exarch : Protoxylem toward periphery and metaxylem towards centre; in, roots., Phloem :Phloem consists of sieve tube elements, companion cells, phloem, fibres and phloem parenchyma; Phloem transports the food material from leaves, to various parts of the plant., (a) Sieve tube elements :, long tube like structures arranged longitudinally., associated with companion cells., end walls are perforated to form sieve plates., functions of sieve tubes are controlled by the nucleus of companion cells., (b) Companion cells, Specialised parenchymatous cells associated with sieve tube elements, Connected with sieve tube elements by pit fields present between their, common longitudinal walls, Help to maintain pressure gradient in sieve tubes., (c) Phloem Parenchyma, made up of elongated, tapering cylindrical cells with dense cytoplasm and, nucleus., cell wall made of cellulose with pits through which plasmodesmatal, connections exist between cells., store food material., (d) Phloem fibers (bast fibers), are sclerenchymatous; absent in primary phloem but present in secondary, phloem., elongated, unbranched pointed, needle like apices with thick cell walls., , Protophloem : First formed phloem with narrow sieve tubes., , Metaphloem : Later formed phloem with bigger sieve tubes., , The Tissue System :, 1. Epidermal tissue system : It includes cuticle, epidermis, epidermal hairs,, root hairs, trichomes and stomata., , The Tissue System :, (1) Epdiermal tissue system : It includes., (a) Cuticle—Waxy thick layer outside epidermis, prevents the loss of water., (b) Epidermis : Outer most layer of primary plant body., (c) Epidermal hair : help in absorbing water and mineral from soil., (d) Trichomes : help in preventing water loss due to transpiration., Anatomy of Flowering Plants, , 63
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(e) Stomata : Regulate process of transpiration and gaseous exchange., Stomatal apparatus : The stomatal aperture, guard cells and surrounding, subsidiary cells are together called stomatal apparatus., Subsidiary Cells, , Epidermal Cells, , Guard Cells, Nucleus, Stomatal Pore, , Chloroplast, Open Stomata, , 2. The ground tissue system : It is made up of parenchyma, collenchyma,, sclerenchyma. In dicot stems and roots (both monocots and dicots) the ground, tissue is divided into hypodermis, cortex, endodermis, pericycle, medullary, rays and pith., 3. The vascular tissue system : It includes vascular bundles which are made, up of xylem and phloem., Vascular Bundles, Radial bundles, , Conjoint bundles, , (Xylem and phloem occur, on different radii), , (Xylem and phloem are situated at, the same radius of vascular bondle), , Xylem, Phloem, Collateral bundles, (Open with, cambium), , (Closed, without cambium), , Concentric, bundles, , Xylem, , Phloem, Vascular, Cambium, , Bicollateral, bundles, , Phloem, , Cambium, Phloem, , Xylem, , (a), Phloem, , (b), Xylem, , 64, , Biology Class - 11, , Xylem
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Anatomy of Root, , , Dicot Root , , Monocot Root, , 1. Cotext is comparatively narrow., 1. Cortex is very wide., 2. Endodermis is less thicknened, 2. Endodermal cells are highly, casparian strips are more thickened Casparian strips are visible, prominent. only in young roots., 3. The xylem and phloem bundles, 3. Xylem and phloem are more than 6, varies from 2 to 5. (polyarch)., 4. Pith is absent or very small., 4. Well developed pith is present., 5. Secondary growth takes place, 5. Secondary growth is absent., with the help of vascular cambium, and cork cambium., Casparian Strips—The tangential as well as radial walls of endodermal, cells of dicot roots have deposition of water impermeable, waxy material, suberin, in the form of casparian strips., , Antomy of Stem, , , Dicot Stem , , Monocot Stem, , 1. The ground tissue is differentiated 1. The ground tissue is made up of similar, into cortex, endodermis,pericycle cells., and pitch, 2. The vascular bundles are arranged 2. The vascular bundles are scattered, in a ring. throughout the ground tissue., 3. Vascular bundles are open, without 3. Vascular bundles are closed,, surrounded, bundle sheath and wedge-shaped by sclerenchymatous bundle sheath,, outline. oval or rounded in shape., 4. The stem shows secondary growth 4. Secondary growth is absent., due to presence of cambium, between xylem and phloem., Secondary growth dicot stem—An increase in the girth (diameter) in, plants. Vascular cambium and cork cambium (laternal meristems) are involved, in secondary growth., Anatomy of Flowering Plants, , 65
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1. Formation of cambial ring : Intrafascicular cambium + interfascicular, cambium., 2. Formation of secondary xylem and secondary phloem from cambial ring., 3. Formation of spring wood and autumn wood., 4. Development of cork cambium(phellogen), , Cork (phellem) – From outer cells, Cork Cambium (Phellogen), , Sec. cortex (phelloderm) – from inner cells, (Phellogen + Phellem + Phelloderm) = Periderm, , Secondary growth in dicot roots : Secondary growth in dicot roots occur, with the activity of secondary meristems (vascular cambium). This cambium, is produced in the stele and cortex, and results in increasing the girth of dicot, roots., , Anatomy of Leaf, Dorsiverntral (Dicot) Leaf Isobilateral (monocot) Leaf, 1. Stomata are absent or less abundant 1. The stomtata are equally distributed, on the upper side. on both sides., 2. Mesophyll is differentiated into two 2. Mesophyll is undifferentiated., parts upper palisade parenchyma, and lower spongy parenchyma., 3. Bunldle sheath is single layered and 3. Bundle sheath may be single or, formed of colourless cells. double layered., 4. Hypodermis of the mid-rib region, is 4. Hypodermis of the mid-rib region, collenchymatous. is sclerenchymatous., 5. Stomata have kidney shaped guard 5. Stomata have dumb bell shaped, cells. guard cells., , 1., 2., 3., 4., 5., , Spring Wood , , Also called early wood., Cambium is active, Xylary elements more, Vessels with wide cavities, Light in colour, low density, , 66, , Biology Class - 11, , Autumn Wood, , 1. Also called late wood, 2. Cambium less active, 3. Xylary elements less, 4. Vessels narrow, 5. Dark, high denisty
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Heartwood , , Sapwood, , 1. Central or innermost region of stem 1. Peripheral region stem, light in, which is hard, durable and resistant colour, to attack of Microorganisms and, insects., 2. Not involved in conduction of water, 2. Involved in conduction of water and, gives mechanical support to stem mineral, Lenticels—Produced when phellogen cuts off parchymatous cells on outer, side. These cells rupture the epidermis forming lens shaped opening called lenticels., Function—Permit exchange of gases., Bulliform Cells—Large, empty, colourless adaxial cells with vein in leaves, which maintain turgidity of leaves., , Questions, , Very Short Answer Question, , (1 mark each), , 1. Name the tissue represented by the jute fibres used for making the ropes., 2. Which kind of roots have polyarch vascular bundles ?, 3. Write the significance and location of heart wood., 4. State the role of pith in stem., 5. Where are bulliform cells found in leaves ?, 6. Why are xylem and phloem called complex tissues ?, 7. Which meristem is responsible for longitudinal growth in plants ?, 8. What forms’ the cambial ring in a dicot stem during the secondary, growth ?, 9. Name the anatomical layer in the root from which the lateral branches of, root originate., 10. Which tissue of the leaf contains chloroplast ?, 11. A plant tissue when stained, showed the presence of hemicellulose and, pectin in cell wall of its cells. Name the tissue., 12. Write the function of phloem parenchyma., 13. Name the cells which make the leaves curl in plants during water stress., 14. Give the function of lenticels., Anatomy of Flowering Plants, , 67
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15. The vascular bundles are surrounded by a thick layer of cells in leaves. What, is the name of cells ?, 16. Mention the signfiicance of casparian strips. Where do you find them ?, 17. Give the function of companion cells., , Short Answer Questions (SA-I), , (2 marks each), , 18. Why is cambium considered to be lateral meristem ?, 19. Give any four differences between tracheids and vessels., 20. How are open Vascular bundles differ from closed vascular bundles ?, 21. What are trichomes ? State their functions., 22. Give below are the various types of tissue and their functions. Which out of, these is not a matching pair arid why;, (a) Collenchyma :, , , provides mechanical support to the, growing parts of plant., , (b) Sclerenchyma :, , photosynthesis, storage and secretion., , (c) Chlorenchyma :, , perform the function of photosynthesis, , (d) Xylem :, , conduction of water and minerals., , 23. In which part of the plant you would see the following :, (a) Radial vascular bundle, , Short Answer Question (SA-II), , (b) Well developed pith, , (3 marks each), , 24. Give the points of difference between lenticels and stomata., 25. Even being a monocotyledonous plant the Palm increases in girth. Why and, how does it take place ?, 26. Differentiate between endarch and exarch conditions., 27. If you are provided with microscopic preparation of transverse section of a, meristemic tissue and permanent tissue, how would you distinguish them ?, 28. Differentiate between aerenchyma and collenchyma on the basis of their, structure and function., 29. Are there any tissue elements to pholoem which are comparable to those of, xylem ? Explain., 68, , Biology Class - 11
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30. Observe the figure and answer the following questions :, (i) Name parts (a) and (b)., (ii) Are these types of stomata observed in monocot or in dicot plants ?, (iii) Which parts of stomata constitute the stomatal apparatus ?, , Long Answer Questions, 31., , , 32., , (5 marks each), , (i), (ii), (iii), (i), , What are meristems ?, Name the various kinds of meristems in plants., State the location and functions of meristems., Suppose you are examining a cross section of a stem under compound, microscope, how would you determine whether it is monocot stem or dicot, stem ?, (ii) Write the characteristics of collenchyma., 33. What is secondary growth in plants ? Describe various steps of secondary, growth in dicot stem with the help of diagrams., , Answers, , Very Short Answers , , (1 mark each), , 1. Sclerenchyma., 2. Monocotyledonous roots., 3. The hard central region of tree trunk made up of xylem vessels, which provide, mechanical strength to stem., 4. Pith stores the food material., 5. Bulliform cells are found in the upper epidermis of monocot leaves., 6. As they are made up of more than one kind of cells., 7. Primary meristem., Anatomy of Flowering Plants, , 69
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8., 9., 10., 11., 12., 13., 14., 15., 16., 17., , Fascicular and intrafascicular strips of meristem., Pericycle of mature zone., Mesophyll tissue., Collenchyma., Lateral conduction of food and supply of water from xylem., Bulliform or motor cells., Permit exchange of gases., Bundle sheath cells., Casparian strips are found in endodermis and make them water impermeable., Maintain pressure gradient in sieve tubes., , Short Answers (SA-I), , (2 marks each), , 18. The cambium is considered as a lateral meristem because it occurs along the, lateral sides of the stem and roots and appears later than primary meristem., Cells of this meristem divide periodically and increase the thickness of the, plant body., 19., , 1., , 2., , 3., 4., , Tracheid , , Vessels, , A tracheid is formed from a, 1. A vessel is made of a number of, single cell. cells., The ends are rounded or, 2. The ends are generally oblique and, transverse. tapering., They are comparatively narrower. 3. They are comparatively wider, The lumen is narrower., 4. The lumen is wide., , 20. Open Vascular bundles : These vascular bundles contain a strip of cambium, in between phloem and xylem. Open vascular bundles are collateral and, bicollateral., , Closed Vascular bundles : Intrafascicular cambium is absent. Closed, vascular bundles can be collateral or concentric., 21. Trichomes are multicellular epidermal hairs on the stem, seeds or fruits., Trichomes help in protection, dispersal of fruits and seeds and reduction in, water loss., 22. (b) Sclerenchyma : photosynthesis, storage and secretion is not a matchingpair., The function of sclerenchyma is to provide mechanical support to, organs., 23. (a) Root, (b) Monocot root, 70, , Biology Class - 11
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Short Answers (SA-II), , (3 marks each), , 24. Lenticels : Opening that are found in old stems and roots in the cork tissues, containing a number of complimentary cells and they are permanently opened, pores., , Stomata : Opening that are found in leaves and young stems in the epidermis, and have two guard cells. They open and close in response to turgidity of, their guard cells., 25. Palms possess residual meristem below their leaf primordial, which adds, ground parenchyma and vascular bundles. The ground parenchyma can also, undergo further divisions even after the completion of elongation., 26., , Endarch condition, , Exarch condition, , , 1. Protoxylem towards pith and, 1. Protoxylem towards periphery and, metaxylem towards periphery metaxylem towards pith, 2. Found in Stem, 2. Found in root., 27. Meristematic tissues are composed of cells that have the capability to divide., These cells are exist in different shapes without intercellular space. Cells are, thin walled, rich in protoplasm, without vacuoles., , Permanent tissues are derived from meristematic tissue and are composed, of cells have their definite shape, size and function. These cells may be thin, walled (living) or thick walled (dead)., 28., , Arenchyma , , Collenchyma, , , (a) Parenchymatous tissue containing (a) Tissue contains deposits of, large air space. cellulose and large pectin at the, corner of cells., (b) Thin walled cells, isodiametric in (b) Consists of oval and polygonal, in shape with intercellular space. cells without intercellular space., (c) Provides buoyancy to the plant., (c) Provides elasticity and mechanical, , strength., 29. (a) The sieve elements of phloem is comparable to the vessel of the xylem because, both lack nucleus., (b) Pholem fibre is similar to the xylem fibre because both provide tensile strength, to the tissue., (c) Phloem parenchyma and xylem parenchyma is the living components, of phloem and xylem respectively., Anatomy of Flowering Plants, , 71
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30. (i) a : epidermal cell, , , b : guard cell, , (ii) In dicot plants., (iii) The stomatal apparatus includes the stomatal aperture, guard cells and, the surrounding subsidiary cells., , Long Answers, , (5 mark each), , 31. (i), (ii) and (iii) : Refer ‘Points to remember’, 32. (i) and (ii) : Refer ‘Points to remember’., 33., , , , Secondary growth : Refer ‘Points to remember., , Steps of secondary growth : Refer page 94–97, NCERT, Text Book of, , Biology for Class XI., Figure 6.9, page 95 NCERT, Text Book of Biology for Class XI., , , , 72, , Biology Class - 11
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Points to Remember, Cell junctions—In nearly all animal tissues, specialised junction provide, structural and functional links between its individual cells., Three Types of Cell junctions—, 1. Tight junctions : Plasma membranes of adjacent cells are fused at intervals., They help to stop substances from leaking across a tissue., 2. Adhering junctions : Perform cementing function to keep neighbouring, cells together., 3. Gap junction : Facilitate the cells to communicate with each other by, connecting the cytoplasm of adjoining cells for rapid transfer of ions, small, molecules and soometimes big molecules., Types of Fundamental Animal Tissues, S.No. , , Type, , 1. Epithelial Tissues, , Location, , Functions, , Free Surfaces, , Protection, Secretion,, , , , Excretion, absorption,, , , , Sensory and reproduction, , 2. Connective Tissues, , Inside body, in organs, , Holding or binding, support,, , , , other tissues and below, , transport and circulation,, , , , skin, , protection and storage., , 3. Muscular Tissues, , Inside movable parts, , Movements and locomotion, , 4. Nervous Tissues, , Central Nervous System, , Communication and control, , , , & every organ Peripheral, , , , Nervous System., Structural Organisation in Animals, , 73
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Animal Tissues, Epithelial, , Connective, , Muscular, , Neural, , Epithelial Tissue, (A) Simple : Composed of single layer of cells., , , , , Functions as lining for body cavities, ducts and tubes., , 1. Squamous, , , , single thin layer of flattened cells., , , , found in walls of blood vessels, air sacs of lungs., , , , single layer of cube like cells., , , , found in ducts of glands and tubular parts of nephron., , , , single layer of tall and slender cells., , , , , , free surface may have microvilli., , , , , , found in lining of stomach and intestine, , , , columnar or cubolidal cells with cilia., , , , move particles or mucus in specific direction, in, , , 2. Cuboidal, , 3. Columnar, , 4. Ciliated, , , bronchioles, fallopian tubes., , (B) Compound :, , , Made of more than one layer of cells., , , , Provide protection against chemical and mechanical stresses., , , , Cover dry surface of skin, moist cavity, pharynx, inner lining of ducts of, salivary glands and pancreatic ducts., Glandular epithelium, , , , Exocrine glands, , Endocrine glands, , secrete mucus, saliva,oil, milk, , secrete hormones., digestive enzymes, products released through ducts., , secrete directly into the fluid, bathing the gland., , , 74, , Biology Class - 11
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Connective tissue : Link and support other tissues/organs of the body., Connective Tissues, Proper Connective Tissues, Loose connective, Tissues, , Specialised Connective Tissues, , Dense connective, Tissues, , Skeletal, Tissues, , Areolar Adipose Dense, Dense Bone, regular, irregular, , eg. Tendon, ligament, , Cartilage, , Fluid Connective, issues, Blood, , Lymph, , Loose Connective Tissue, , (has cells and fibres loosely arranged in semi-fluid ground substance), (i) Areolar Tissue :, present beneath the skin., , contains fibroblasts, macrophages and mast cells., , serves as a support framework for epithelium, (ii) Adipose Tissue :, , , located beneath the skin., , cells are specialised to store fats., , Dense Connective Tissue, , , Fibres and fibroblasts are compactly packed., (i) Dense Regular, , , Collagen fibres present in rows., , , Tendons attach skeletal muscle to bone., , Ligaments attach bone to bone., , (ii) Dense Irregular, , Has collagen fibres and fibroblasts oriented differently., , , This tissue is present in the skin., , , Specialised Connective Tissues, (i) Cartilage : made up of chondrocytes and collagen fibres; inter cellular, material is solid and resists compression. Present in tip of nose outer ear, joints, etc., Structural Organisation in Animals, , 75
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(ii) Bones : Ground substance is rich in calcium salts and collagen fibres Osteocyt, es are present in launae. Bones support and protect softer tissues and organs., They interact with skeletal muscles to bring about movements. Bone marrow, in some bones is the site of blood cell formation., (iii) Blood : Fluid coonective tissue, consists of plasma and blood cells., Vascular Tissues, , , Blood, , Plasma, , , Lymph, Formed, Elements, , Blood Corpuscles, , Plasma, , Leucocytes, , Blood Platelets, , Erythrocytes, Leucocytes, (RBCs) (WBC), , Neutrophils, , Granulocytes, Eosinophils, , Agranulocytes, Basophils, , Monocytes, , Lymphocytes, , MUSCULAR TISSUES, (long, contractile cells called fibres, bring about movement and locomotion), Skeletal Muscle Smooth Muscle Cordiac Muscle, Striated, Non-striated, Striated with intercalated, disc for communication, Closely attached to, Forms wall of, Occurs in heart wall, sekeletal bones., Internal Organs Short cyclindrical, like blood vessels uninucleated fibres, stomach, intestine, long cylindrical, Spindle like, multinucleated fibres, uninucleated fibres., , , 76, , Biology Class - 11
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Neural Tissues, , , Neurons are the functional unit and are excitable cells., , , , Neurogila cells make up more than half the volume of neural tissue., , They protect and support neurons., Cockroach— Periplaneta americana (Phylum-Arthropoda, Class-Insecta), Habitat : Cockroach is a terrestrial, nocturnal, ominivorous,unisexual,, oviparous insect. Body convered by a chitinous, hard exoskeleton of hard plates, called sclerities., Morphology :, Head : Triangular, formed by fusion of 6 segments. Bears a pair of antennae,, compound eyes. Mouth parts consists of labrum (upper lip), a pair of mandibles,, a pair of maxillae,labium (lower lip), hypharynx (acts as tongue)., Thorax : 3 segments; prothorax, measothorax and metathorax., Bears 2 pairs of wings :, Forewings : tegmina (mesothoracic)., Hindwings : transparent, membranous (metathoracic), 3 pairs of legs in thoracic segments. (one pair in each thoracic segment.), Abdomen : 10 segments. Bears a pair of long, segmented anal cerci in, both sexes and a pair of short, unjoined anal styles in males only 7th segment is, boat shaped., Also has anus and genital aperture at the hind end. Genital aperture, surrouonded by external genitalia called gonapophysis or phallomere., , , Male Cockroach , , Female Cockroach, , 1. Abdomen long and narrow, , 1. Abdomen short and broad, , 2. All nine sterna visible, , 2. Seven sterna visible. (7th sternum fused, with 8th and 9th sterna), , 3. Anal style present, , 3. Anal style absent, , Anatomy : Study of the morphology of internal organs., Alimentary canal : Divided into foregut, midgut and hindgut., Mouth → Pharynx → Oesophagus → Crop (stores food) → Gizzard (grinding, of food) → Hepatic caecae (at junction of fore and midgut; secretes digestive, juice) → Hindgut (ileum, colon, rectum) → Anus., Structural Organisation in Animals, , 77
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Head, Glandular Portion, Salivary Reservoir, Oesophagus, Crop, Gizzard, Hepatic caecae, Midgut, Malpighian Tubules, Ileum, Colon, Rectum, Anus, , Alimentary Canal of Cockroach, Blood vascular system : Open type, visceral organs bathed in haemolymph, (colourless plasma and haemocytes)., Heart consists of enlongated muscular tube and differentiated into funnel, shaped chambers with ostia on either side. Blood from sinuses enters heart through, ostia and is pumped anteriorly to sinuses again. Blood is colourless (haemolymph)., Repiratory system : Network of trachea which open through 10 pairs of, spiracles. Spiracles regulated by sphincters. Oxygen delivered directly to cells., Excretion and osmoregulation : by malpighian tubules; uricotelic (Uric, acid as excretory proudct)., Nervous system : Consists of series of fused segmentally arranged ganglia, joined by paired longitudinally connectives on the ventral side, three ganglia in, thorax, six in abdomen. Brain represented by supraoesophageal ganglion. Each, eye consist s of 200 hexagonal ommatidia., , Reproductive system :, Male reproductive system : Pair of testes (4th-6th segments) → vas deferens, → ejaculatory duct → male gonophore., Glands–Seminal vesicle (stores sperms), mushroom shaped gland (6th-7th, segment)., 78, , Biology Class - 11
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Female reproductive system :, A pair of ovaries (with 8 ovarian tubules) → Oviduct → Genital chamber., Sperms transferred through spermatophores female produces 9–10 Ootheca., Fertilised eggs encased in capsules called oothecae (contains 14-16 eggs on, an average) development of P. americana paurometabolous incompleted, metamorphosis). Nymph grows by moulting 13 times to reach adult form., Interaction with man, , Pests as destroy food and contaminate it., , Can transmit a variety of bacterial diseases (Vector)., , Questions, Very Short Answer Questions, 1., 2., 3., 4., 5., 6., 7., 8., 9., 10., 11., , (1 mark each), , Name the tissue which contains Haversian canals., Mention two special properties of nervous tissues., Name the large cells present in adipose tissue., Name the cells responsible for clotting of blood., What are exocrine glands ?, Differentiate between tendon and ligament., Where are RBC’s formed ?, A muscular fiber having no striations and tapers at both ends. Name it., Mention the site,where sclerite is present in cockroach., Name the mouth part of cockroach which is comparable to our tongue., “Sexual dimorphism is found in cockroach”. Explain the statement., , Short Answer Questions–I, , (2 marks each), , 11. What is the function of ciliated epithelium ? Where do we find this, epithelium ?, 12. What are the two types of fibres of connective tissues ? Distinguish between, the two., 13. To which tissue do the following belong to :, (a) Osteocytes, (b) Chondrocytes, (c) Neuroglia, (d) Intercalated discs, 14. Give the location of hepatic caecae in cockroach ? What is their function ?, 15. Name the locomotory appendages of cockroach on the basis of external, morphology., Structural Organisation in Animals, , 79
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Short Answer Questions–II, , (3 marks each), , 16. Differnetiate between skeletal and smooth muscles., 17. Differntiate between male and female cockroach on the basis of external, morphology., 18. (a) What is open circulatory system ?, (b) Explain the respiratory system of cockroach., 19. (a) Give the common name of Periplaneta americana., (b) How many spermathecae found in cockroach ?, (c) What is the position of ovaries in cockroach ?, (d) How many segments are present in the abdomen of cockroach ?, (e) Where do you find malpighian tubules ?, (f) What is mosaic vision ?, 20. Name the different cell junctions found in tissues., 21. Mention the special features of eye in cockroach., 22. Write the appropriate type of tissue in column B accounting to the functions, mentioned is column A., , Column A , Column B, a. Linking and supporting frame work, ......................, b. Protective covering , ......................., c. Secretion and absorption ......................., , Long Answer Questions, , (5 marks each), , 23. (a) What is compound epithelium ? What are their main function ?, (b) Where do we find areolar tissue ?, (c) How is adhering junction different from gap junction ?, 24. Make a neat and well labelled diagram showing alimentary canal of cockroach., , Answers, Very Short Answers, 1., 2., 3., 4., 5., 80, , Mammalian bone., Excitability and conductivity., Adipocytes., Blood platelets., Glands which discharge their secretions into ducts., Biology Class - 11, , (1 mark each)
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6. Tendon Ligament, , Attach skeletal muscles to bones, , Attach bone to bone, , 7. Bone narrow, 8. Smooth or non striated muscle fibre., 9. In the exoskeleton all over the body., 10. Hypopharynx = lingua, 11. Male and female cockroaches show morphological differences., , Short Answers–I, , (2 marks each), , 11. Refer ‘Points to Remember’., 12. White and yellow fibres. White fibres are thin, unbranched, inelastic, occur, in bundles and formed of protein collagen. Yellow fibres are thick, straight,, elastic, branched, occuring singly, formed of protein elastin., 13. (a) Bone tissue, , (b) Cartilage, , (c) Neural tissue, , (d) Cardiac muscle, , 14. Refer ‘Points to Remember’., 15. Three pairs of legs and two pairs of wings., , Short Answers-II, , (3 marks each), , 16. Refer ‘Points to Remember’., 17. Refer ‘Points to Remember’., 18. Refer ‘Points to Remember’., 19. (a) American Cockroach., (b) One pair, present in 6th segment., (c) Between 2nd and 6th abdominal terga., (d) 10 segments., (e) At the beginning of ileum in cockroach., (f) Vision where several images of an object are formed by compound eye., Helps to detect movement of objects very efficiently., 20. (i) Gap junctions, , (ii) Tight junctions, , (iii) Adhering junctions, Structural Organisation in Animals, , 81
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21. See text in NCERT at page No. 114., (i) Situated at dorsal surface of head., (ii) Each eye consists of about 2000 hexagon ommatidia., (iii) It can receive several images of an object., (iv) This kind of vision is known as mosaic vision., (v) It is more sensitivity but less resolution., 22. (a) Connective tissues, (b) Stratified epithelium, (c) Columnar epithelium, , Long Answers , , (5 marks each), , 23. Refer ‘Points to Remember’., 24. Refer Fig. 7. 16 NCERT Text Book of Biology class-XI., , , 82, , Biology Class - 11
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Points to Remember, Cell Theory : Cell Theory was formulated by Scheleiden and Schwann, and, was modified by Rudolf Virchow. Cell theory States., (A), , All living organisms are composed of cells and products of cells., , (B), , All cells arise from pre-existing cells., , Cell : Cell is the structural and functional unit of life., , , Prokaryotic Cell , , Eukaryotic Cells, , , , Generally small sized (1–10 µm), , , , Generally large sized (5–10 µm), , , , Well defined nucleus absent, , , , Well defined nucleus present, , , , Membrane bounded cell organelles, , , , Membrane bounded cell organelles, , absent present, , , DNA without histone covering, , , , DNA with histone covering, , , e.g., Bacteria, Mycoplasma, Blue e.g., Amoeba, Euglena and other, green Algae higher organism, Gram Positive Bacteria Gram Negative Bacteria, , , Bacteria that take up gram, , , , Bacteria do not take up gram stain, , Stain. e.g., Bacillus e.g., Escherichia Coli, , PROKARYOTIC CELL :, Modification of cell envelope, , , Slime layer : Glycocalyx in form of loose sheath., , , , Capsule : Glycocalyx in form of thick and tough sheath., , , , Mesosomes : Extension of plasma membrane. These can be in the form of, vesicles, tubules and lamellae., Cell : The Unit of Life, , 83
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Functions : Cell wall formation, DNA replication and distribution to daughter, cells, respiration, secretion processes, to increase surface area of plasma, membrane and enzyme content., Flagella : Extension of cell wall. It is composed of three structure–filament,, hook and basal body. They help in motility of bacteria., Pili and fimbriae : Surface structure of some bacteria which attaches them, to rocks in streams and to host tissues., Genetic Material : It is not covered by nuclear envelope. In addition to the, genomic DNA (the single chromosome/circular DNA), many bacteria have small, circular self replicating, double straned DNA which is called as plasmid, plasmid, contain genes like antibiotic resistance., Eukaryotic cells, Possess an oragnized nucleus with nuclear envelope and have a variety of, complex locomotory and cytoskeletal structures., Cell Membrane—Singer and Nicolson (1972) gave ‘fluid mosaic model’., According to this the quasi-fluid nature of lipid enables lateral movement of, proteins within the overall bilayer; two types of proteins (Peripheral and integral, proteins) with cholesterol, glycolipids and glycoporteins. Erythrocyte membrane, has 52% protein and 40% lipids., Function—It is semi permeable and helps in transport of molecule across it., , Passive transport , Active transport, Transport of molecules from, Transport of molecules from lower to, higher to lower concentration. higher concentration, It do not utilise energy (ATP)., It utilises energy (ATP), , e.g., diffusion , e.g., Na+/k+ ATPase Pump., , Fluid Mosaic Model of Plasma Membrane, 84, , Biology Class - 11
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Cell Wall is non-living rigid structure which gives shape to the cell and, protects cell from mechanical damage and infection, helps in cell-to-cell interaction, and provides barrier to undsirable macromolecules., Cell wall of algae is made of cellulose, galactans, mannans and minerals like, calcium carbonate. Plant cell wall consists of cellulose, hemicellulose, pectins, and proteins., Middle lamella is made of calcium pectate which holds neighbouring cells, together., Plasmodesmata connect the cytplasm of neighbouring cells., Endoplasmic Reticulum (ER), Consists of network of tiny tubular structure. ER divides the intracellular, space into two distinct compartments–luminal (inside ER) and extra luminal, (cytoplasm)., (i) Rough Endoplasmic Reticulum (RER) :, Ribosomes attached to outer surface., Function : Involved in protein synthesis and secretion., (ii) Smooth Endoplasmic Reticulum (SER) : Lack ribosomes., Function Site for synthesis of lipid., Golgi apparatus : First observed by Camillo Golgi (in 1898), Consist of cisternae stacked parallel to each other. Two faces of the organelle, are convex/cis or forming face and concave/trans or maturing face., Functions : Performs packaging of materials, to be delivered either to the, intra-cellar targets or secreted outside the cell. Important site of formation of, glycoproteins and glycolipids., Lysosomes :, Membrane bound vesicular structures formed by the process of packaging, in the golgi apparatus. Contain hydrolysing enzymes (lipases, proteases,, carbohydroses) which are active in acidic pH. Also called ‘Suicidal Bag’., Function : Intracellular digestion., Vacuoles : Member bound space found in the cytoplasm. Contain water, sap,, excretory product, etc. In plant cell, vacoule occupies 90% of space., Function : In plants tonoplast (single membrane of vacuole) faciliates, transport of ions and other substances., Contractile vacuole for excretion in Amoeba and food vacuoles formed in, protists for digestion of food., Cell : The Unit of Life, , 85
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Mitochondria : Double membraned structure. Outer membrane smooth and, inner membrane forms a number of infoldings called cristae The inner compartment, is called matrix. The cristae increase the surface area., DNA (Circular), OUTER MEMBRANE, RIBOSOME (70S), CRISTA, MATRIX, INNER MEMBRANE, OUTER MEMBRANE, Mitochondria, Mitochondria, , Function : Sites of aerobic respiration. Called ’power houses’ of cell as, produce cellular energy in the form of ATP. Matrix possesses single circular DNA, molecule, a few RNA molecules, ribsomes (70S). It divides by binary fission., Plastids : Found in plant cells and in euglenoides. Chloroplasts, chromoplasts, and leucoplasts are 3 types of plastids depending on pigments contained., Types of Plastids, Chloroplast, Chromoplast, Leucoplast, (green coloured plastids), carotenoid (fat souble, Amyloplast (Starch), contains chlorophyll, double carotene (give colour to plant parts) Elaioplasts (oil + fat), stranded DNA and 70S, Xanthophylls., Aleuroplast, ribosomes, , Others (Yellow, red, orange), , (store proteins), , Function : Site of photosynthesis, and imparts colours to fruits and flowers., , Chloroplast, 86, , Biology Class - 11
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Ribosomes, Composed of RNA and proteins; without membrane. Eucaryotic ribosomes, are 80S. S = Svedberg’s unit), Function : Site of protein synthesis., Cytoskeleton : Network of filaments., Proteinaceous structure in cytoplasm made up of microtubules and micro, filaments., Function : Mechanical support, motility, maintenance of the shape of the cell., Cilia and Flagella, Cilia are small structures which work like oars which help in movement., Flagella are longer and responsible for cell movement. They are covered, with a plasma membrane. Core is called axoneme which has 9 + 2 arrangement, of axonemal microtubules., , Centrosome and Centrioles, Centrosome contains two cylindrical structures called centrioles. Surounded, by amorphous pericentriolar material. Has 9 + 2 arrangement. Centrioles form the, basal body of cilia or flagella and spindle fibres for cell division in animal cells., They produces spindle apparatus during cell divison., Nucleus : With double membrane with perinuclear space and nuclear pores;, has Chromatin, nuclear matrix and nucleoli (site for rRNA synthesis). (Named, by Robert Brown – 1831), Chromatin DNA + nonhistone proteins. (Named by Flemming), Nucleoplasm – Nucleolus + Chromatin, Nulear membrane—It is with perinuclear space and nucleopores., Chromosomes—DNA/RNA + Histone protein/Nonhistone protein., Centromere : Primary constriction–disc is known as kinetochores., No nucleus in Erythrocyctes (RBC) of mammals and sieve tubes in vascular, plants., Chromosomes (on basis of position of centromere) :, Metacentric : Middle centromere., Sub-metacentric : Centromere nearer to one end of chromosomes., Acrocentric : Centromere situated close to its end., Telocentric :Has terminal centromere., Satellite : Some chromosomes have non-staining secondary constructions at, a constant location, which gives the appearance of small fragment called satellite., Cell : The Unit of Life, , 87
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Questions, , Very Short Answer Questions, , (1 mark each), , 1., 2., 3., 4., 5., , Name the parts of bacterial flagella., Name the nutrient stored in (i) elaioplasts (ii) aleuroplasts, Name the scientist who first saw and described a living cell., What are plasmids ?, Name the scientist who first explained that new cells arose from pre-existing, cells (Omnis cellula-e-cellula), 6. What is the composition of plasma membrane of human erythrocyte., 7. Eukayotic ribosomes are 80S. What does ‘S’ stand for ?, 8. Write the function of cytoskeleton in a cell ?, , Short Answer Questions–I, 9., 10., 11., 12., 13., 14., 15., 16., , , , , 17., , , , (2 marks each), , What are nuclear pores ? State their function., State the cell theory., Differentiate between active and passive transport., Differentiate between RER and SER., List two functions of golgi apparatus., List two functions of mesosome., Differentiate between the electron microscopic structure of cilia/flagella and, centriole., Give the specific terms for the following :, (a) Cluster of ribosomes found in cytoplasm, (b) Extensive infolding to the inner membrane of mitochondria, (c) Stacks of closely packed thylakoids, (d) Stalked particles on the inner membrane of mitochondria, (a) Write the function of inclusion bodies in prokaryotic cells ?, (b) Where are they present ?, (c) Give two examples of inclusion bodies., , Short Answer Questions–II, , (3 marks each), , 18. With the help of labelled diagram explain the ‘fluid mosaic model’ structure, of cell membrane., 19. Differentiate between a prokaryotic and eukaryotic cell., 20. What are lysosomes ? How are they formed ? Write their functions., 21. Give the structural details of an eukaryotic nucleus along with its diagram., 88, , Biology Class - 11
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22. The ribosomes of prokaryoters are of 70 S type ribosomes and 80 S type, while of eukaryotes are of 80S type., (a) Give the composition of 70 S type ribosomes and 80 S type risbosome, (two sub units, from each of them are made of), (b) Name two cell organelles of eukaryotic cells which have their own, independent ribosomes of 70 S type, , Long Answer Questions , 23., , , 24., , (5 marks each), , (a), (b), (c), (a), , Give the structural details of mitochondria., Draw its diagram., Why is it called ‘powerhouse of the cell’ ?, Diagrammatically represent the types of chromosomes based on the, position of centromere., (b) What does chromatin contain ?, (c) What is perinuclear space ?, , Answers, , Very Short Answers, 1., 2., , 3., 4., 5., 6., 7., 8., , (1 mark each), , Filament, hook, basal body., Elaioplasts : fats and oils., Aleuroplasts : proteins., Anton Von Leeuwenhoek, The small circular DNA, outside the genomic DNA of bacteria., Rudolf Virchow., 52% proteins, 40% lipids., Sedimentation coefficient (Svedberg unit), Mechanical support, motility, maintenance of shape of cell., , Short Answers–I , , (2 marks each), , 9. Minute pores present in the nuclear envelope; provide passage for movement, of RNA and proteins between nucleus and cytoplasm., 10. Refer ‘Points to Remember’., 12. Refer ‘Points to Remember’., 13. Refer ‘Points to Remember’., 14. Refer ‘Points to Remember’., Cell : The Unit of Life, , 89
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15. , , Flegella/Cilia Centriole, , , (i) Possess (9 + 2) pattern of axoneme, , , : Possess (9 + 0) pattern,, , microtubules enclosed by a membrane membrane less organelle, , (ii) Each tubule is doublet, , : Each tubule is a triplet, , 16. (a) Polyribosome/Polysome, (b) Cristae, (c) Grana, (d) Fo–F1 particles ..., 17. (a) Reserve materials are stored,, (b) They are free in the cytoplasm, (c) e.g.,Phosphate granules, cyanophycean granules, glycogen granules., , Short Answers–II, , (3 marks each), , 18. Refer page no. 131–132, NCERT, Text Book of Biology for Class XI., 19. Differences in nucleus/chromosomes/mesosome/membrane bound cell, organelles/ribosomes/compartments in cell., 20. Refer page no. 134 NCERT, Text Book of Biology for Class XI., 21. Refer page no. 138, NCERT, Text Book of Biology for Class XI., 22. (a) 70 S ribosomes have 50 S and 30 S sub units; 80S ribosomes have 60, S and 40 S sub units., (b) Mitochondria and chloropolast., , Long Answers, , (5 marks each), , 23. Refer page no. 134-135, NCERT, Text Book of Biology for Class XI., 24. Refer page no. 138–139, NCERT, Text Book of Biology for Class XI., , , 90, , Biology Class - 11
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Points to Remember, Biomolecules : All the carbon compounds that we get from living tissues., Biomicromolecules : Molecules which have molecular weights less than, one thousand dalton. They are also known as monomers., Biomacromolecules : Have molecular weight more than 10000 daltons, generally 10,000 deltons and above. They are generally polymers., , Primary and secondary metabolites :, , , , , Primary metabolites have identifiable functions and play important roles in, normal physiological process eg. Amino acids, nitrogenous bases, proteins, and nucleic acid., Secondary metabolites are product of certain metabolic pathways from, primary metabolites, eg. carotenoids, drugs, alkaloids, essential oils, rubber,, gum, cellulose and resins etc., , , Amino acids : Organic compounds containing an amino group and one, carboxyl group (acid group) and both these groups are attached to the same, carbon atom called α carbon and so they are called amino acids., , , e.g. (1) In Glycine R = H, (2) In alaine R = CH3, (3) In serine R = CH2 – OH, Biomolecules, , 91
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Twenty types of amino acids., Amino acid exists in Zwitterionic form at different pHs., , R, R, R, , |, |, |, , , , , , (A), , (B), (C), (Zwitterionic form), Based on number of amino and carboxyl groups, amino acids can be :, (i) Aromatic–Tryptophan, phenylalanine and Tyrosine are aromatic (give, , smell) amino acids., Amino Acids, Polar, Acidic, e.g. aspartic acid, , Basic, e.g., Arginine, , Neutral, e.g. valine, Proline, , glutamic acid, (ii) Non Polar—Glutamine, tyrosine, serine, , Lipids :, Water insoluble, containing C, H, O., Fats on hydrolysis yield fatty acids., Fatty acid has a carboxyl group attached to an R group (contains 1 to 19, carbons)., Fatty Acids : Saturated : With single bonds in carbon chain, e.g., Palmitic, acid, butyric acid., , Unsaturated : With one or more double bonds, e.g., oleic acid, linoleic acid., Glycerol : A simple lipid, is trihydroxy propane., , , , , Some lipid have fatty acids esterified with glycerol. , , Example of fatty acid (Palmitic acid) (CH3—(CH2)14—COOH), 92, , Biology Class - 11
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, , They can be monoglycerides, diglycerides and triglycerides., 1, , 2, , 3, , Triglyceride (R1, R2, R3 are alkye groups in fatty acids.), Phospholipids (Lecithin) found in cell membrane and lipids made complex, structure in neural tissue., Phospholipids are compound lipids with phosphorus and a phosphorylated, organic compound e.g., Lecithin., Nitrogen bases, (Carbon compounds with heterocyclic rings), , Purine : Adenine, Guanine,, Pyrimidine : Cytosine, Uracil, Thymine., Lipids are not strictly macromolecules as their molecular weight do not, exceed 800 Da but form a part of the acid insoluble pool., Biomacromolecules : Biomolecules a with molecular weights in the, range of ten thousand daltons and above; found in acid insoluble fraction. e.g., polysaccharides, nucleic acids, proteins and lipids., Nucleic acids : Deoxyribonucleic acid (DNA) and ribonucleic acid (RNA)., Nucleoside : Nitrogenous base + Sugar e.g. Adenosine, guanosine., Nucleotide : Nitrogenous base + Sugar + Phosphate group. e.g. Adenylic, acid, Guanylic acid. Thymidylic acid., DNA structure (Watson and Crick Model) : DNA is a right handed, double, helix of two polynucleotide chains, having a major and minor groove. The two, chains are antiparallel, and held together by hydrogen bonds (two between A, and T and three between C and G). The backbone is formed by sugar-phosphatesugar chain. The nitrogen bases are projected more or less perpendicular to this,, backbone and face inside. The pitch is 34A°. At each step of ascent, the strand, turns 36°. The rise per base pair is 3.4°A, so one full turn involves ten base pairs., Protein : proteins are polypeptides., They are polymers of aminoacids linked by peptide bond., Is a heteropolymer (different monomers repeating ‘n’ number of times)., For functions of proteins refer Table 9.5, Page no. 147 NCERT, Text Book, of Biology for Class XI., Biomolecules, , 93
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Structure of Proteins, (a) Primary structure : Is found in the form of linear sequence of amino acids., First amino acid is called N-terminal amino acid and last amino acid is called, C-terminal amino acid., (b) Secondary structure : Polypeptide chain undergoes folding or coiling which, is stabilized-by hydrogen bonding. Right handed helices are observed; e.g.,, fibrous protein in hair, nails., (c) Tertiary structure : Long protein chain is folded upon itself like a hollow, woollen ball. Gives a 3-dimensional view of protein, e.g., myosin., (d) Quaternary structure : Two or more polypeptides with their foldings and, coilings are arranged with respect to each other, e.g., Human haemoglobin, molecule has 4 peptide chains - 2 α and 2 β submits., , Monosaccharides are joined by glycosidic acid bond, right end is reducing, and left end is non reducing, Polysaccharides : Are long chain of polymers of monosaccharides., (a) Starch : Store house of energy in plant tissues. Forms helical secondary, structures, made of only glucose monomers., (b) Cellulose : Homopolymer of glucose. It does not certain complex helices., Cotton fibre is cellulose., (c) Glycogen : Is a branched homopolymer, found as storage polysaccharide in, animals., (d) Inulin : Is a polymer of fructose., (e) Chitin : Chemically modified sugar (amino-sugars) N-acetyl galactosamine, form exoskeleton of arthropods; heterpolymer., , Metabolic Pathways :, (a) Anabolic pathways : Lead to formation of more complex structure from a, simpler structure with the consumption of energy, e.g., Protein from amino, acids., also known as biosynthetic pathways., (b) Catabolic pathway : Lead to formation of simpler structure from a complex, structure, e.g., Glucose → Lactic Acid + energy, The most important energy currency in living systems is ATP (adenosine, tri – phosphate)., “There is no uncatalysed metabolic conversion in living system”, The living state is a non-equilibrium steady state to be able to perform work., Without metabolism, there cannot be a living state., 94, , Biology Class - 11
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Bonds linking monomers in a polymer, Peptide bond—formed between the carboxyl (–COOH) group of one amino, acid, and the amino (– NH2) group of the next amino with the elimination of water, moiety, (dehydration)., Glycosidic bond—bond formed between two carbon atoms of two adjacent, monosaccharides., by dehydration., Phosphodiester bond—bond formed in nucleic acids where in a phosphate, moiety links the 3-carbon of one sugar of one nucleotide to the 5-carbon of the, sugar of the succeeding nucleotide. (The bond between phosphate group and, hydroxyl group of sugar), Ezymes : Are biocatalyst., Almost all enzymes are proteins., Ribozymes–Nucleic acid that behave like enzymes., Has primary, secondary and tertiary structure., Active site of an enzyme is a crevice or pocket into which substrate fits., Enzymes get damaged at high temperatures., Enzymes isolated from thermophilic organisms (live under high temperatures), are thermostable., Enzymes accelerate the reactions many folds., Enzymes lower the activation energy of reactions. (Fig. 9.6, Page no. 156,, NCERT Text Book of Biology for Class XI)., E + S == ES → EP → E + P, where E = Ezymes, S = Substrate, P = Product, , Factors affecting enzyme activity :, (a) Temperature : Show highest activity at optimum temperature. Activity, declines above and below the optimum value., (b) pH : Enzymes function in a narrow range of pH. Highest activity at optimum, pH. (Fig. 9.7, Page no. 157, NCERT, Text Book of Biology for Class XI)., Biomolecules, , 95
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(c) Concentration of substrate : The velocity of enzymatic reaction rises with, increases in substrate concentration till it reaches maximum velocity (Vmax)., Further increase of substrate does not increase the rate of reaction as no free, enzyme molecules are available to bind with additional substrate., Enzyme inhibition : When the binding of a chemical shuts off enzyme, activity, the process is called inhibition and chemical is called inhibitor., Competitive inhibition : Inhibitor closely resembles the substrate in its, molecular structure and inhibits the enzyme activity. E.g., inhibition of succinic, dehydrogenase by malonate. (Actual is succinic acid)., , Classification of enzymes :, 1. Oxidoreductase/dehydrogenases : Catalyse oxidoreduction between 2, substrates. S reduced + S′ oxidised → S′ oxidised + S′ reduced., 2. Transferases : Catalyse transfer of a group between a pair of substrates., S – G + S′ → S + S′ – G, 3. Hydrolases : Catalyse hydrolysis of ester, ether, peptide, glycosidic, C–C,, P-N bonds., 4. Lyases : Catalyse removal of groups from substrates by mechanisms other, than hydrolysis. Leave double bonds., 5. Isomerases : Catalyse inter-conversion of optical, geometrical or positional, isomers., 6. Ligases : Catalyse linking together of 2 compounds., C–O, C–S, C–N, P–O, Co-factors : Enzymes becomes catalytically become active when it binds, to non protein constituent called co-factors. Protein portion of enzyme is, called apoenzyme., , , Prosthetic group : These are organic compound which tightly bound to the, apoenzyme., , , e. g., Haem is prosthetic group in peroxidase and catalase., 96, , Biology Class - 11
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, , Coenzyme : These are organic compounds whose association with the, apoenzyme is only transient, usually occurring during the course of catalysis., , , e.g., Coenzyme Nicotinamide adenine dinucleotide (NAD) and NADP, contain vitamin niacin., , , Metal ions : Metal ions form coordination bond with side chains at the, active site and at the same time form one or more coordination bond with, substrate., , , e.g. zinc in enzyme carboxy peptidase., , Questions, Very Short Answer Questions, , (1 mark each), , 1. Why do oils generally remain in liquid state even in winters ?, 2. Name an element found in proteins but not in lipids and carbohydrates., 3. What is the difference between RNA and DNA in terms of nitrogenous base ?, 4. What does an enzyme do in terms of energy requirement of a reaction ?, 5. What is the function of ATP in cell metabolism ?, 6. Name the protein which form the intercellular ground substance., 7. What are biomacromolecules ?, 8. Why enzymes are called bio-catalysts ?, , Short Answer Questions-I , , (2 marks each), , 9. Differentiate between prosthetic group and coenzyme ?, 10. What are glycosidic bonds and peptide bonds ?, 11. Why are aminoacids also known as substituted methane?, 12. Amino acids exist as zwitter ions. Give its structure. Why is it formed ?, 13. Why do starch give blue black colour with iodine ?, Biomolecules, , 97
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14. Why are starch and glycogen more suitable than glucose as a storage, product ?, 15. What would happen when salivary amylase which acts on starch in mouth, enter in stomach ?, 16. Differentiate between homo polysaccharides saccharides and hetero poly, saccharides., 17. Why do physicians recommend vegetable oils rich in polyunsaturated fat, for persons suffering from cardiovascular diseases ?, 18. Why does the shelf life of fruits and vegetables increase in a refrigerator ?, , Short Answer Questions-II , , (3 mark each), , 19. Differentiate between primary and secondary metabolites with examples ?, 20. List out some major proteins and their function ?, 21. Explain the structure of proteins., 22. Explain Watson-Crick model on DNA structure., 23. Explain peptide bond, glycosidic bond and phospodiester fond., 24. Explain competitive inhibition along with an example., , Long Answer Questions , , (5 marks each), , 25. List the 6 classes of enzymes along with their functions., , Answers, Very Short Answer , , (1 marks each), , 1. Oils are unsaturated lipids, hence have lower melting points., 2. Nitrogen., 3. RNA has uracil instead of thymine., 4. Lowers the activation energy of reaction., 5. Are the energy currency of cell., 98, , Biology Class - 11
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6. Collagen., 7. Refer point to remember., 8. Enzymes are proteins that catalyze metabolic/chemical reactions inside the, living being. That’s why they are called biocatalysts., , Short Answer-I , , (2 marks each), , 9. Refer ‘Points to remember’., 10. Refer, ‘Points to remembers’., 11. The α-carbon has 4 substituted groups occupying the 4 valency positions :, H,—COOH,—NH2 and—R group., 12., +, , 3, , , Due to ionizable nature of — NH2 and — COOH groups., 13. Starch form helical secondary structure which can hold I2., 14. Occupy lesser space as less bulky and can be hydrolysed to glucose when, required., 15. In mouth, salivary amylase changes starch into maltose. Action of amylase, stops in stomach as it cannot act in an acidic medium., 16. Homopolysaccharides, , Heteropolysaccharides, , (a) Constituted of single type, , Constituted by two or more type of, , , , monosaccharide unit and their, derivatives, , of monosaccharide units, , (b) e.g., starch, glycogen, cellulose, , e.g., Peptidoglycans, chitin, , 17. Polyunsaturated oils contain fatty acids having one or more double bonds, which does not clog arteries due to high proportion of polyunsaturated fatty, acids., , Biomolecules, , 99
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18. Low temperature prevents growth of food spoiling micro organisms and, also inhibits the action of enzymes present in the food, because, enzymes, are inactivated at low temperature., , Short Answers-I, , (3 marks each), , 19. Secondary metabolites—The metabolites like alkaloids lectins Drugs,, Pigments, Spices and scents etc. which are useful to human welfare and, have ecological importance., , Primary metabolites—The metabolites having identifiable functions and, play important role in normal physiological processes, e.g., sugars, amino, acids, fats and oils and nucleotides, etc., 20. Refer Page No. 147, Table 9, 5, NCERT, text book of biology class XI., 21. Refer ‘Points to remember’., 22. Refer ‘Points to remember’., 23. Refer Page No. 151. NCERT, Text Book of Biology for Class XI., 24. Refer ‘Points to remember’., , Long Answers , , (5 marks each), , 25. Refer Page No. 158., NCERT, Text Book of Biology for Class XI., , , 100, , Biology Class - 11
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Points To Remember, Cell cycle : The sequence of events by which a cell duplicates its genome,, synthesises the other constituents of the cell and eventually divides into two, daughter cells., Interphase (G1 phase + S phase + G2 Phase), , Phases of cell cycle, , Karyokinesis division of nucelues, M Phase (Mitosis phases), , Interphase : (Resting Phase), , , Cytokinesis division of cytoplasm, , G1 Phase : Cell metabolically active and grows continuously but does not, replicate DNA, , , , S Phase : DNA synthesis occurs, DNA content increases from 2C to 4C, but, the number of chromosomes remains same i.e., 2n., , , , G2 Phase : Proteins are synthesised in preparation for mitosis while cell, growth continues., M Phase (Mitosis Phase) : Starts with nuclear division, corresponding to, , separation of daughter chromosomes (karyokinesis) and usually ends with division, of cytoplasm, (cytokinesis)., Quiescent stage (G0) In adult animals cells that do not divide and exit G1, phase to enter an inactive stage called G0. Cells at this stage remain metabolically, active but do not proliferate., Cell Cycle and Cell Division, , 101
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e.g., Heart cells, , M. Phas, , e, , G2 phase, RNA and, Protein synth, , Anaphase, Telo, pha, Cy, se, tok, ine, sis, , ase, Proph, Metaphase, , Karyokinesis, , se, , ha, , P, Go, , ng, ati, n, ll i repe le, e, c, C ell y, C ll C, Ce, Death Cell, at last, , Growth and, Differentiation, , Synthesis, S Phpse, DNA Dupliates, Replication of, Chromosomes, , G1 Phase, Protein Synthesis, Growth of nucleus, , (1) Interphase, G1 phase, S phase, G2 -phase, (2) M-phase, , Cell Cycle, , Mitosis, Since the number of chromosomes in the parent and progeny cells is the, same, it is called as equational division. Mitosis is divided into four sub stages., 1. Prophase : (i) Replicated chromosomes, each consisting of 2 chromatids,, condense and become visible., (i) Microtubules are assembled into mitotic spindle., (iii) Nucleolus and nuclear envelope disappear., (iv) Centriole moves to opposite poles., 2. Metaphase : (i) Spindle fibres attached to kinetochores (small disc-shaped, structures at the surface of centromere) of chromosomes., (ii) Chromosomes line up at the equator of the spindle to form metaphase, plate., 3. Anaphase : (i) Centromeres split and chromatids separate., (ii) Chromatids move to opposite poles due to shortening of spindle fibres., 4. Telophase : (i) Chromosomes cluster at opposite poles., (ii) Nuclear envelope assembles around chromosomes clusters’., (iii) Nucleolus, Golgi Complex, E.R. reforms., 102, , Biology Class - 11
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Cytokinesis : Is the division of protoplast of a cell into two daughter cells, after karyokinesis (nuclear division), Animal Cytokinesis :, Appearance of furrow in plasma membrane which deepens and joins in the, centre, dividing cell cytoplasm into two., Plant cytokinesis : Formation of new cell wall begins with the formation, of a simple precursor — cell plate which represents the middle lamella between, the walls of two adjacent cells., , , When karyokinesis is not followed by cytokinesis, a multinucleated condition, arises. This is called syncytium., , Significance of Mitosis :, 1., 2., 3., 4., , Growth-addition of cells., Maintenance of surface/volume ratio. Maintain Nucleo–cytoplasmic ratio., Maintenance of chromosomes number., Regeneration., Cell Cycle and Cell Division, , 103
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5. Reproduction in unicellular organisms, lower plants and some insects., 6. Repair and wound healing., 7. Vegetative reproduction in plants takes place by mitosis., , Meiosis :, , , , , , , , , , , Specialised kind of cell division that reduces the chromosomes number by, half. hence it is called reductional division., Occurs during gametogenesis in plants and animals., Involves two sequential cycles of nuclear and cell division called Meiosis I, and Meiosis II., It results in 4 haploid daughter cells., Interphase occurs prior to meiosis which is similar to interphase of mitosis, except the S phase is prolonged., , Meiosis I, Prophase I : Subdivided into 5 phases., (i) Leptotene :, , Chromosomes make their appearance as single stranded structures., , , Compaction of chromosomes continues., (ii) Zygotene :, , Homologous chromosomes start pairing and this process of association, , is called synapsis., , , Chromosomal synapsis is accompanied by formation of synaptone-mal, complex., , , Complex formed by a pair of synapsed homologous chromosomes is, called bivalent or tetrad., (iii) Pachytene : Crossing over occurs between non-sister chromatids of, homologous chromosomes. The enzymes involved in the process is, ‘recombinase’. Recombination between homologous chromosomes is, completed. Exchange of genetic material., (iv) Diplotene : Dissolution of synaptonemal complex occurs and the recombined, chromosomes separate separate from each other except at the sites of crossing, over. These X-shaped structures are called chaismata. In oocytes of some, vertebrates diplotene can last for month or years., , 104, , Biology Class - 11
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(v) Diakinesis : Terminalisation of chaismata., , Chromosomes are fully condensed and meiotic spindles assembled., , Nucleolus disappear and nuclear envelope breaks down., , Metaphase I : Bivalent chromosomes align on the equatorial plate., Microtubules from opposite poles of the spindle attach to the pair of, homologous chromosomes., Anaphase I : Homologous chromosomes, separate while chromatids remain, associated at their centromeres., , Telophase I :, Nuclear membrane and nucleus reappear., Cytokinesis follows (diad of cells)., Interkinesis : Stage between two meiotic divisions, (meiosis I and meiosis II), generally short lived., Meiosis II: (It resembles the normal mitosis)., , , Prophase II, Nuclear membrane disappears., Chromosomes again become compact., Metapahse II, Chromosomes align at the equator., Microtubules from opposite poles of spindle get attached to kinetochores of, sister chromatids., Anaphase II, Simultaneous splitting of the centromere of each chromosome, allowing, them to move towards opposite poles of the cell., Telophase II, Two groups of chromosomes get enclosed by a nuclear envelope., Cytokinesis follows resulting in the formation of tetrad of cells i.e., 4 haploid, cells., , , Significance of Meiosis, 1. Formation of gametes : In sexually reproducing organisms., 2. Genetic variability : Variations are very important for evolution., 3. Maintenance of chromosomal number : By reducing the chromosome, number in gametes. Chromosomal number is restored by fertilisation of, gametes., Cell Cycle and Cell Division, , 105
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Questions, Very Short Answer Questions , 1., 2., 3., 4., 5., 6., , (1 mark each), , What are kinetochores ?, Name the term used for the stage between two meiotic divisions., Why is mitosis called equational division ?, Name the stage of meiosis during which synaptonemal complex is formed., What is Go phase of cell cycle ?, Where does mitosis take place in plants and animals ?, , Short Answer Questions-I , , (2 marks each), , 7. Differentiate between cytokinesis of plant and animal cell., 8. What is chaismata ? State its significance., 9. Differentiate between chromatin and chromatid., 10. Give the terms for the following :, (a) The period between 2 successive mitotic divisions., (b) Cell division in which chromosome number is halved., (c) Phase in cell cycle where DNA is synthesised., (d) Division of nuclear material., 11. What happens during S phase of interphase ?, 12. Distinguish between metaphase of mitosis and metaphase I of meiosis., 13. What will be the DNA content of a cell at G1 after S and G2 if the content, after M phase is 2C., , Short Answer Questions-II , , (3 marks each), , 14. Differentiate between mitosis and meiosis., 15. List the significance of mitosis., 16. Describe the following :, (a) Synapase, (b) Bivalent, (c) Leptotene, , Long Answer Questions , , (5 marks each), , 17. With the help of labelled diagram, explain the following :, (a) Diplotene, (b) Anaphase of mitosis, (c) Prophase I of meiosis, 106, , Biology Class - 11
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18. What is cell cycle ? Explain the events occuring in this cycle., 19. With the help of labelled diagrams, explain various stages of mitosis cell, divsion., 20. (a) Write a note on significance of meiosis., (b) Differentiate between anaphase 1 of meiosis and Anaphase of mitosis., (c) In which phase of interphase duplication of DNA will occur ?, , Answers, Very Short Answers, , (1 mark each), , 1., 2., 3., 4., 5., , Small disc-shaped structure at the surface of the centromeres., Interkinesis., The chromosomes number is daughter cells is equal to that of the parent., Zygotene., Cells which enter a stage where they are Metabolically active but no longer, proliferate., 6. Plant – Meristematic tissue; Animals–somatic cells., , Short Answers-I , , (2 marks each), , 7. Refer ‘Points to Remember’., 8. Refer ‘Points to Remember’., 9. Chromatin Chromatid :, , (a) Diffuse, deep staining hereditary material longitudinally split half of a, chromosome, light staining hereditary material., (b) Metabolically inert Metabolically active., 10. (a) Interphase, (b) Meiosis, (c) S phase, (d) Karyokinesis, 11. Refer ‘Points to Remember’ :, 12. , , Metaphase , , Metaphase I, , (a) Chromosome align along, (a) Bivalent chromosomes arrange, the equator of the cell along the equatorial plane., (b) Figure 10.2 (b) page 165, Text (b) Figure 10.3, meta phase I page 169,, Book of Biology for Class XI NCERT Text Book of Biology for, Class XI., Cell Cycle and Cell Division, , 107
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13. G1 – 2C, S1 – 4C, G2 – 4C, , Short Answers-II , 14. , (a), (b), , (c), , (d), , (3 marks each), , Mitosis , Occurs in Somatic cells, (a), Number of chromosomes, (b), remain same in daughter cells , No exchange of genetic, (c), material , Involve single division, (d), , Meiosis, , Occurs in germ cells, Number of chromosomes reduces, to half in daughter cells., Exchange of genetic material occurs, due to crossing over, Involve two successive division, , 15. Refer ‘Points to Remember’., 16. Refer ‘Points to Remember’., , Long Answer , , (5 mark each), , 17. Refer ‘Points of Remember’., 18. Refer ‘Points of Remember’., 19. Refer ‘Points of Remember’., 20. (a) Refer ‘Points of Remember’, (b) Refer ‘Points of Remember’., (c) During A phase or synthesis phase., , , 108, , Biology Class - 11
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Points To Remember, , Translocation (Long distance transport) : Transport of substances in, plants over longer distances through the vascular tissue (Xylem and Phloem), The transport of water and mineral in Xylem is unidirectional while transport of, organic and mineral nutrients in phloem is multi-directional., Means of transport (Short distance transport) : The transport of material, into and out of the cells is carried out by a number of methods. These are diffusion,, facilitated diffusion and active transport., (i) Diffusion : Diffusion occurs from region of higher concentration to region, of lower concentration across the permeable membrane. It is passive and slow, process. No energy expenditure takes place., Factors affecting diffusion : Permeability of membrane, Temperature,, pressure, gradient of concentration and the size of substances., (ii) Facilitated diffusion : The diffusion of hydrophilic substances along, the concentration gradient through fixed membrane transport protein without, involving energy expenditure. For this the membrane possess aquarporins and, ion channels. No ATP energy is utilized in this process., Porins—The proteins that form huge pores in the outer membranes of the, plastids, mitochondria and some bacteria which allow the small size molecules, to pass through., Aquaporins—Proteins that facilitate diffusion of water molecules through/, across the plasma membrane of cell., Methods of Facilitated Diffusion, Symport, , Antiport, , Uniport, , (Two molecules cross the, (Two molecules move (Single molecule moves, membrane in the same, in opposite direction at across membrane indpendirection at the same time.) the same time.), dent of other molecules.), Transport in Plants, , 109
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Transport Proteins—They are present in the membrane. They allow the, passage of substances through membrane., (i) Carrier Proteins—They bind to the particular solute particle to be, transported and deliver these to other side of membrane., (ii) Channel Proteins—Ion Channel—They are specific for different ions like, K+, Cl–,, Water Channel—Surrounded by eight proteins called aqua protein and, allow passage of water or water soluble substance., (iii) Active transport : Active transport is carried by the movable carrier, proteins (pumps) of membrane. Active transport uses energy to pump molecules, against a concentration gradient from a low concentration to high concentration, (uphill-transport). It is faster than passive transport., , Different Transport Mechanisms, S., Property, No. , 1., , 2., 3., , , , , , , , , , , , Required Special, membrane protein, Uphill transport, Requires ATP Energy, , Simple, Diffusion, , Faciliated, Transport, , Active, Transport, , No, , Yes, , Yes, , No, No, , No, No, , Yes, No, , Water potential—(ψw)–Greater the concentration of water in a system,, greater is its kinetic energy and greater is the water potential. It is measured, in pascal (Pa). or mega pascal., If two systems are in contact, then there is movement of water from the, solution with higher potential to lower water potential., Solute potential—(ψs)–Magnitude of lowering of water potential, when a, solute is added to the water., Pressure Potential—(ψp)—Magnitude of increase of water potential, when, pressure greater than atmospheric pressure is applied to pure water or a, solution., Water potential of pure water is zero (0)., Solute potential is always negative (–) and pressure potential is always, positive (+)., ψw = ψs + ψp, , 110, , Biology Class - 11
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Osmotic Pressure—External pressure applied to prevent the diffusion of, water. It depends upon solute concentration., Numerically, osmotic pressure is equal to osmotic potential. Osmotic pressure, has positive (+) sign. Osmotic potential has negative (–) sign., Turgor Pressure—Due to osmotic entry of water, the protoplasm of a plant, cell presses the cell wall towards the outside with a force, it is called Turgor, Pressure., Diffusion Pressure—The pressure exerted by the tendency of the particles to, diffuse from the area of higher concentration to lower concentration. It is directly, proportional to the concentration of particles of diffusing substance., Osmosis : Osmosis is movement of solvent or water molecules from the, region of their higher diffusion pressure or free energy to the region of their lower, diffusion pressure of free energy across a semipermeable membrane., Water molecules move from higher water potential to lower water potential, until equilibrium is reached., Plasmolysis : Process of shrinkage of protoplast in a cell due to exosmosis, in hypertonic solution. If a plasmolysed cell is placed in water or a hypotonic, solution it becomes turgid., Hypotonic solution : The external solution which is more dilute than the, cytoplasm., Hypertonic solution : The external solution, which is more concentrated, than the cytoplasm., Isotonic solution : When the external solution balances the osmotic pressure, of the cytoplasm., Casparian strip : It is the tangential as well as radial walls of endodermal, cells having the deposition of water impermeable suberin., Imbibition : Imbibition is the phenomenon of absorption of water by the, solid particles of an adsorbent causing it to enormously increase in volume without, forming a solution., , , Some examples of Imbibition :, (i) If a dry piece of wood is placed in water, it swells and increases in its volume., (ii) If dry gum or pieces of agar-agar are placed in water, they swell and their, volume increases., (iii) When seeds are placed in water they swell up., (iv) Swelling of wooden door during rainy season., , Conditions essential for imbibition, 1. Water potential gradient between the surface of the adsorbent and the imbibed, liquid, is essential., 2. Affinity between the adsorbent and the imbibed liquid., Transport in Plants, , 111
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Transport of water in plants : Water is absorbed by root hairs by diffusion., Then water moves upto xylem by two pathways–apoplast and symplast pathway., Apoplast Pathway—Movement occurs through the intercellular spaces or, walls of the cell, without entering the cytoplasm. This movement is fast. In roots,, movement of water occurs via apoplast except at the carparian strip, most of water, enters through apoplast., Symplast Pathway—Water enters the cell through cell membrane and travels, intercellularly through plasmodesmata. This movement is slow. At casparian strip, region water moves through symplast., Symplastic pathway, Cortex, Endodermis, Phloem, Root Hair, , Xylem, Pericycle, Casparian Strip, Epidermis, Apoplastic Pathway, , Apoplastic And Symplastic Pathways of Water Transport, Ascent of Sap—Upward movement of water in the form of dilute solution of, mineral ions from roots to the top aerial parts of plants through tracheary elements, of xylem against the gravitational force is called ascent of sap. It involves two, theories—, (i) Cohesion—Tension-transpirtation pull theory., (ii) Root pressure theory., (1) Cohesion-Tension-transpiration pull theory—, (i) Continuity of water column—The transport of water to the top of trees, occurs through xylem vessels. The forces of adhesion and cohesion maintain a, thin and unbroken column of water in the capillaries of xylem vessels through, which it travels which is travels upward. Water is mainly pulled by transpiration, from leaves., (ii) Transpiration Pull—Transpiration accounts for loss of 99% of water in, the form of water vapours the surface of leaves. The loss is mainly through stomata., Pull of water as a result of tension created by transpiration is the major diving, force of water movement upward in a plant., Three physical properties of water which affect the ascent of xylem sap due, to transpiration pull., 112, , Biology Class - 11
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(iii) Cohesion force or Tensile strength of water—, Cohesion—Mutual attraction between water molecules., Adhesion—Attraction of water molecules to polar surface., Surface tension—Attraction of water to each other in liquid phase to a, greater extent than to water in gaseous phase., (2) Root pressure Theory : A hydrostatic pressure existing in roots which, pushes the water up in xylem vessels upto certain height to herbaceons plant., Guttation : The water loss in its liquid phase in the form of water droplets at, night and early morning through special openings of vein near the tip of leaves., These opening are called hydathodes., Transpiration : The loss of water through stomata of leaves and other aerial, parts of plants in form of water vapours., Factors affecting transpiration : Temperature, light, relative humidity, wind, speed, number and distribution of stomata, water status of plant, canopy structure., Significance of transpiration—Advantages—Helps in ascent of sap removal, of excess water, cooling effect, distribution of mineral salts, supply water for, photosynthesis., Disadvantages—May cause reduced growth, wilting (loss of turgidity),, reduced yield and waste of energy., Since there are advantages as well as disadvantages of transpiration so—, ‘Transpiration is called a necessary evil’., Opening and closing of stomata—Mechanism of opening and closing of, stomata involves two steps—, (i) Change to the turgidity of gaurd cells., (ii) Orientation of cellulose microfibrils in the cell wall of gaurd cells., Endosmosis—When a cell is placed in water or hypotonic solution, water, enters into the cell. This in called endosmosis. Due to it the volume of cell increases, and it creates turgor pressure., Exosmosis—When a cell is placed in hypertonic solution, water comes out, of the cell, this is called exosmosis. It decreases volume of the cell., Uptake and transport of mineral nutrients—Ions are absorbed by the roots, by passive and active transport. The active uptake of ions require ATP energy., Specific proteins in membranes of root hair cells activity pump ions from the soil, into the cytoplasm of epidermal cells and then xylem. The further transport of ions, to all parts of the plant is carried through the water stream. Older dying leaves, export much of their mineral content to younger leaves. Elements phosphorus,, sulphur, nitrogen and potassium are most readily mobilised., Transport in Plants, , 113
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Mass flow : Mass flow is the movement of substances (water, minerals and, food) in bulk from one point to another as a result of pressure differences between, two points., , The pressure or mass flow Hypothesis :, Leaf Mesophyll Cells, Photosynthesis, ↓, Glucose, ↓, Sucrose, ↓, Rise in Osmotic Pressure, ↓, Endosmosis, ↓, Rise in T.P. of Mesophyll Cells, ↓, Mass flow of H2O and Sucrose due to turgor gradient, ATP, ADP + ip, “In masse” comes in companion cell, and then into sieve tube cells, ↓, 114, , Biology Class - 11, , Loading
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Water comes in sieve tube cell from, Xylem and increase turgor Pressure gradient, ATP, ADP + i, Sucrose comes to Root cell and, convert into starch or energy or get, consumed in Respiration, , Unloding, , ↓, Decrease in O.P. of Root Cells, ↓, Water moves to Root Xylem, Mycorrhiza—A mycorrhiza is a symbiotic association of a fungus with a, root system. The fungal hyphae absorb mineral ions and water from the soil, and, provide them to the roots of plant, in turn the roots provide sugars and nitrogen, containing compounds to the mycorrhizae., , Questions, Very Short Answer Questions , , (1 mark each), , 1. Which part of the root is related with the absorption of water ?, 2. What makes the raisins to swell up when kept in water ?, 3. Casparian strip is made of a substance which is impervious to water. Name, this substance., 4. What will happen to water potential when a solute is added to water ?, 5. A plant cell when kept in a solution got plasmolysed. What was the nature, of the solution., 6. Mention two ways of absorption of water by root hairs in plants., 7. Which form of sugar is transported through phloem ?, 8. Give one example of imbibition., Transport in Plants, , 115
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9. A flowering plant is planted in an earthen pot and irrigated. Urea is added, to make the plant grow faster, but after some time the plant dies. Give its, possible reason., 10. Why is energy required to develop root pressure ?, 11. Correct the statements :, (a) Imbibition is a special type of diffusion when water is absorbed by, living cell., (b) Most of water flow in the roots occurs via symplast., (c) Cells shrink in hypotonic solution and swell in hypertonic solution., , Short Answer Questions-I , , (2 marks each), , 12. A well watered potted herbaceous plant shows wilting in the afternoon of a, dry sunny day. Give reason., 13. Do different species of plants growing in the same soil show the same rate, of transpiration at a particular time ? Justify your answer., 14. What is casparian strip ? Write its significance in plants., 15. Xylem transport is unidirectional and phloem transport bi-directional, why ?, 16. How is transpiration different from guttation ? Give two points., 17. Suggest two methods to increase the life of cut plants in a vase., 18. Write the chemical composition of xylem and phloem sap., 19. Transpiration is a necessary evil in plants. Explain., , Short Answer Questions-II, , (3 marks each), , 20. Why is solute potential always negative ? Explain., ψw = ψs + ψp, 21. Water has a very important role in sustaining the life list properties of water, which make it useful for all biological processes on earth., 22. When any dry plant material or seeds is/are kept in water, they swell up., (a) Name the phenomenon involved in this change., (b) Define this phenomenon., (c) Give two conditions essential for the phenomenon to occur., 23. Differentiate between temporary and permanent wilting. Do any of them, indicate the water status of the soil ?, 116, , Biology Class - 11
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24. Observe the diagram and answer the following :, , (a) Which of these guard cells show a higher water content, A or B ?, (b) Are these types of guard cells found is monocots or dicots ?, (c) Name the element which play an important role in the opening and, closing of stomata., 25. What is mycorrhiza ? How is the mycorrhizal association helpful in absorption, of water and minerals in plants ?, 26. Observe the given figure and give the answers of the following :, (a) Identify the process occurring in (I), (II) and (III)., (b) Differentiate between the process II and III., (c) How many types of aquaporins from the water channels in the cell, membrane., , 27. Give scientific term for the following statements/processes :, (a) Movement of water in roots exclusively, through the cell wall, (b) The positive hydrostatic pressure developed inside the cell or cell wall., (c) A solution having relatively less concentration., (d) Loss of water vapour from the aerial parts of the plants in the form of, water vapours., Transport in Plants, , 117
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(e) Movement of a molecule across a membrane independent of other, molecule., (f) Water loss in its liquid phase through the special opening of veins near, the tip of leaves of many herbaceous plants., , Long Answer Questions, , (5 marks each), , 28. Minerals are present in the soil in sufficient amount. Do plants need to adjust, the types of solutes that reach the xylem ? Which molecules help to adjust, this ? How do plants regulate the type and quantity of solutes that reach, xylem., 29. How do plants absorb water ? Explain transpiration pull model in this regard., 30. (a) Describe the pressure flow hypothesis of translocation of sugar in plants., (b) Explain the mechanism of closing and opening of stomata., , Answers, , Very Short Answer, , (1 mark each), , 1., 2., 3., 4., 5., 6., 7., 8., 9., 10., , Root hairs., Endosmosis., Suberin, Water potential will decrease., Hypertonic., Apoplast and symplast pathway., Sucrose., Swelling of seed when put in water/moist soil., Due to exosmosis i.e., water comes out the plant., Every activity requires energy. Root pressure develops due to activity of, living cell., 11. (a) Osmosis is a special type, of diffusion when water is absorbed by living, cells., (b) Most of the water flows in the roots occurs via the apoplast., (c) Cells shrink in hypertonic, solution and swell in a hypotonic solution., , Short Answers-I , , (2 marks each), , 12. During noon, the rate of transpiration becomes higher than the rate of water, absorption by plant. It causes loss of turgidity and leads to wilting., 118, , Biology Class - 11
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13. Rate of transpiration is not same because transpiration is affected by numbers, and distribution of stomata, and their opening., 14. Refer page 185, NCERT, Text Book of Biology for Class XI, 15. Refer page 190, NCERT, Text Book of Biology for Class XI, 16. , , Transpiration, , Guttation, , (i) Loss of water by a plant in form (i) The loss of water in the form of, , , of vapours. liquid droplets from the plant., , (ii) Occurs through the general, , (ii) Occurs at the margins and the, , , , surface of leaves (stomata) and tips of the leaves., , , , the young stems., , 17. (a) By adding cytokinin into water of the vase., (b) Preventing entry of air in the cut plants by immediately immersing the, cut end in water., 18. Xylem Sap-Water, traces of all minerals., Phloem sap-5-10% sucrose, 1% amino acids, traces of bound mineral,, hormones, other organic substances and rest is water., 19. Refer to ‘Points of Remember’ (Significance and disadvantages of, Transpiration), , Short Answers-II, , (3 marks each), , 20. Refer to ‘Points of Remember’. (Solute Potential, Pressure Potential and, Water potential), 21. Refer to ‘Points of Remember’, (Cohesion, Adhesion and surface tension), 22. (a) Imbibition., (b) Refer to ‘Points to Remember.’, (c) Condition necessary to imbibition., , , (i) Water potential between the absorbent and the liquid imbibed., , , , (ii) Affinity between the adsorbent and the liquid imbibed., , Transport in Plants, , 119
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23. , , Temporary wilting, , (i) Plant recovers from temporary, (i), , wilting after sometimes. , , (ii) Much damage is not caused., (ii), (iii) It commonly occurs during, (iii), , mid-day only. , , Permanent wilting, Automatic recovery is not, possible. It may recover if water, is provided soon., Much damage is caused., It occurs throughout day and, night., , When wilting is permanent, water present in soil is largely unavailable form., The soil contains 10-15% water depending, upon its texture., 24. (a) A, (b) Dicots, (c) K+ (Potassium ions), 25. Refer points to remember., 26. (a) (i) Uniport (ii) Antiport (iii) Symport, (b) Refer ‘Points to Remember’., (c) 8 types of aquaporins., 27. (a) Apoplast pathway, (b) Turgor pressure, (c) Hypotonic, (d) Transpiration, (e) Uniport, (f) Guttation, , Long Answers , 28., 29., 30., , , (5 marks each), , Refer page 189, NCERT, Text Book of Biology for Class XI., Refer page 186-187, NCERT, Text Book of Biology for Class XI., (a) Refer points to remember., (b) Refer page 191, NCERT, Text Book of Biology for Class XI., , , 120, , Biology Class - 11
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Points To Remember, Autotroph : An organism that sythesize its required nutrients from simple, and inorganic substance; Example—plants, blue green algae (cyanobacteria), Heterotroph : An organism that cannot synthesise its own nutrients and, depend on others. Example—Bacteria, protists, members of animalia., Biological nitrogen fixation: Conversion of atmospheric nitrogen into, organic compounds by living organisms., Chlorosis : Yellowing of leaves due to loss of chlorophyll., Nitrification : Conversion of ammonia (NH3) into nitrite and then to nitrate., Denitrification : A process of conversion of nitrate into nitrous oxide and, nitrogen gas (N2)., Leg-hemoglobin : Pinkish pigment found in the root nodules of legumes., It acts as oxygen scavenger and protects the nitrogenase enzyme from oxidation., Flux : The movement of ions is called flux. Influx is inward movement of, ions into the cells and efflux is the outward movement of ions., Inhibition of cell division : Deficiency of N, K, S. and Mo., Necrosis : Death of tissues particularly leaf tissue due to deficiency of Ca,, Mg, Cu, K., Delayed Flowering : due to deficiency of N, S, Mo., Mineral Nutrition : Plants require mineral elements for their growth and, development. The utilization of various absorbed ions by a plant for growth and, development is called mineral nutrition of the plant., Hydroponics : Soil-less culture of plants, where roots are immersed, in nutrient solution (without soil) is called hydroponics. The result obtained, from hydroponics may be used to determine deficiency symptoms of essential, elements., Mineral Nutrition, , 121
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Active Transport : Absorption occuring at the expense of metabolic energy., Passive Transport : Absorption of minerals with concentration gradient by, the process of diffusion without the expense of metabolic energy., , Essential Elements, Macronutnents, Macronutrients are present in plant, tissues in concentrations of more, than 10 m mole Kg–1 of dry matter., C, H, O, N, P, K, S, Ca, Mg, , Micro-nutrients, Micro-nutrients are needed in very, low amounts : less than 10 m mole, Kg – 1 matter., Fe, Mn, Cu, Mo, Zn, B, Cl, Ni, , In addition to the 17 essential elements, Na, Si, Co and Si are required by, some higher plants., , Criteria for essentiality :, 1. The element must be necessary for supporting normal growth and reproduction., 2. Requirement must be specific and not replaceable by another element., 3. The element must be directly involved in the metabolism of the plant., Role of Minerals Elements in Plants, MACRO NUTRIENTS, Element, Obtained as, Functions, , , Deficiency, symptoms, , Nitrogen (N), , Stunted growth, Chlorosis,, dormancy of, causal buds., , Mainly as, some, +, as NO2 or NH4, , , Phosphorus (P), , Constituent of cell, membrane. Required, , for the synthesis, , of nucleic acids,, , nucleotides, ATP, , NAD and NADP, , for phosphory , lation reactions., , 122, , Phosphate ions, , Constituent of, proteins, nucleic, acids, vitamins and, hormones., , Biology Class - 11, , Poor growth of, plant., Leaves dull green,, delay in seed, germination purple, or red spots on, leaves, premature, leaf fall.
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Potasium (K), K+, , , , , , , , , Calcium (Ca), Ca2+, , , , , , , , , Magnesium (Mg) Mg2+, , , , , , Helps to maintain an, anion-cation balance, in cells. Involved in, protein synthesis, in, opening and closing, of stomata; activation, of enzymes; maintenance of turgidity of, cells., Required in formation, of mitotic spindle;, involved in normal, functioning of cell, membranes; activates, certain enzymes; as, calcium pectate in, middle lamella of the, cell wall., Activates enzymes in, phosphate metabolism,, constituent of, chlorophyll; maintains, ribosome structure., , Sulphur (S), , , , , , Constituent of two, Chlorosis of, amino-acids-Crysteine younger leaves,, and methionine and, stunted growth, proteins, coenzymes,, vitamins and, , , , ferredoxin., , Stunted growth;, yellow leaves, edges of, leaves; mottled, appearance of, leaves. Premature, death., Stunted growth,, chlorosis of young, leaves., , Chlorosis between, the leaf veins, narcosis purple, colours spots on, older leave, , MACRO NUTRIENTS, Element, Obtained as, Functions, , , Deficiency, symptoms, , Iron (Fe), Fe3+, , , , , , Constituent of, Ferredoxin and, cytochrome; needed, for synthesis of, chlorophyll., , Chlorosis of, leaves, , Manganese (Mn) Mn2+, , , , , , Activates certain, enzymes involved, in photosynthesis,, respiration and nitrogen, metabolism., , Chlorosis, grey, spots on leaves., , Mineral Nutrition, , 123
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Zinc (Zn), Zn2+, , , , , Activates various, enzymes like, carboxylases. Required, for synthesis of auxins., , Malformation of, leaves, , Copper (Cu), Cu2+, Activates certain, , enzymes. Essential for, , overall metabolism, , , , , Stunted growth,, inter-veinal, chlorosis in leaves., Necrosis of the tip, of young leaves,, die back of shoot., , Required for uptake, Boron (B), BO33–, B4O72–, , of water and Ca, for, , membrane functioning,, , pollen germination, cell, , elongation carbohydrate, , translocation., 2+, MoO2 , Molybdenum, (molybdate ions), Activates certain, (Mo) , metabolism., , , , Chlorine (Cl), Cl–, Maintains solute, , concentration along, , with Na+ & K+; maintain, , anion-cation balance, , in cells; essential for, , oxygen evolution in, , photosynthesis., , Death of stem, and root apex,, loss of a foical, dominance,, abscission of, flowers, small size, of fruits, Nitrogen, deficiency interveinal chlorosis, retardation of, growth, Wilted leaves;, stunted root, growth and, reduced fruiting., , Critical Concentration : The concentration of the essential element below, which plant growth is retarted. The element is said to be deficient when present, below the critical concentration., Deficiency symptoms : Chlorosis, stunted growth, premature fall of leaves, and buds and inhibition of cell division., Toxicity of micronutrient : Any mineral ion concentration in tissues that, reduces the dry weight of tissues by 10% is considered toxic. Toxicity of one, element may lead to deficiency of other element since the former may inhibit the, uptake of latter., e.g., Mn competes with Fe, Mg for uptake and also inhibits Ca, translocation to shoot apex. Therefore Mn toxicity symptoms are actually same, as deficiency symptoms of Fe, Mg and Ca., 124, , Biology Class - 11
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The Nitrate so formed can be easily absorbed by the plants and transported, to leaves. In leaves, nitrate is reduced to ammonia to form amino-acids, because, nitrate can not used by plants as such., –, , NO3, , Nitrate reductare, , NADH2 NAD, , Nitrite, Reductare, , –, , NO2, , H2O, , NO3, , Amino acid, Synthesis, , NADH2 NAD, , Denitrification—Process of reduction of the nitrate present in soil to nitrogen., It is carried out by bacteria like Pseudomonas and Thiobacillus., Biological Nitrogen Fixation—Reduction of nitrogen to ammonia by living, organisms. Certain prokaryotes are able to fix nitrogen because of presence of, ‘nitrogenase’ enzyme in them., , Nitrogen fixing microbes may be, (a), , Free living—(i) Aerobic—Azotobacter, (ii) Anaerobic—Rhodospirillum, (b) Cyanobacteria—Nostoc, Anabaena, (c) Symbiotic—(i) With leguminous plants—Rhizobium, (ii) With non-leguminous plants—Frankia, Enzyme nitrogenase—The enzyme nitrogenase is Mo-Fe protein and, catalysis the conversion of atmospheric nitrogen to ammonia (First stable product, of nitrogen fixation), Leg-hemoglobin—A pink colour pigment, similar to hemoglobin of, vertebrates and functions as an oxygen scavenger and protects nitrogenase from, oxygen., N2 + 8e+ + 8H+ 16ATP dinitrogenase 2NH3 + H2 + 16 ADP + 16 Pi, ———→, , Steps of nodule formation :, (a) Rhizobium bacteria present in soil contact a susceptible root hair., (b) Infection of the root hair cause it to curve and deformed due to chemical, secretion., (c) An infection thread is produced carrying the bacteria into the cortex of the, root., (d) The bacteria get modified into rod-shaped bacteria and cause inner cortical, and pericycle cells to divide plant produce cytokinin and auxin to stimulate, cell division and enlarge to form nodules., 126, , Biology Class - 11
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(e) Division and growth of cortical and pericycle cells lead to nodule formation., , (Refer Figure 12.4 page 203 NCERT Text Book), , Mechanisms of N2 fixation, , (a), (b), (c), , It require 3 components—, A strong reducing agent like FADH2, NADPH2, Nitrogenase enzyme, ATP (as energy service), , Steps, (a), (b), (c), , , Formation of Diamide, Formation of Hydrazine (N2H4), Formation of Ammonia,, See Fig. 12.5 Page 203 NCERT, , Questions, , Very Short Answer Questions, , (1 mark each), , 1. Name one symbiotic nitrogen-fixing bacteria., 2. Give two examples of photosynthetic microorganisms, which also fix, atmospheric nitrogen., 3. Name two organisms each which fix nitrogen symbiotically and symbiotically., 4. Which substance impart pink colour to the root nodule of a leguminous plant, and also mention its role ?, Mineral Nutrition, , 127
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5. What is the term used for mineral deficiency symptom in plants in which, leaves become yellow in different pattern ?, 6. Define hydroponics., 7. Give the name of an insectivores angiosperm plant., 8. Give the name of one non-symbiotic nitrogen fixing prokaryote., 9. Name the green house gas produced in rice fields., , Short Answer Questions-I , , (2 marks each), , 10. Differentiate between two types of absorption of minerals in plants from, soil., 11. Name the following :, (a) Bacteria which converts ammonia into nitrite., (b) Bacteria which oxidises nitrite into nitrate., 12. How does Leghemoglobin protect the enzyme nitrogenase ?, 13. Name the enzyme found in root modules for N2 fixation ? Name the pink, coloured pigment required for its functioning., , Short Answer Questions-II, , (3 marks each), , 14. Write the deficiency symptoms of the following three elements :, (a) Phosphorus, (b) Magnesium, (c) Potassium, 15. Describe the following three deficiency symptoms and co-relate them with, concerned mineral deficiency :, (a) Phosphorus, (b) Magnesium, (c) Potassium, 16. Explain in brief the steps involved in biological nitrogen fixation., 17. Describe the two main processes of synthesis of amino acids from Ammonium, ion (NH4+) in plants., 128, , Biology Class - 11
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18. Define critical concentration, also mention four deficiency symptoms of, nutrients in plants., 19. Write a short note on toxicity of micronutrient. Give an example which show, toxicity of one element may lead to deficiency of other element., , Long Answers , , (5 marks each), , 20. Describe all the steps of nitrogen cycle in nature., 21. Describe with diagrams how root nodules are formed in leguminous plants., 22. Explain adaptations in leguminous root nodules for N2 fixation., , Answers, , Very Short Answers, , (1 mark each), , 1. Rhizobium, 2. Anabaena, Nostoc, 3. Asymbiotically-Azotobacter, Bacillus polymyxa Symbiotically-Rhizobium,, Anabaena., 4. Leghemoglobin. It is an oxygen scavenger, which protects the enzyme, nitrogenase., 5. Necrosis., 6. The technique of growing plants in a nutrient solution without soil is called, hydroponics., 7. Nepenthes (Pitcher plant), 8. Azotobacter, 9. Methane (CH4), , Short Answers-I, , (2 marks each), , 10. Refer to NCERT Book, Page no. 200 (12.3)., 11. (i) Nitrifying Bacteria—Nitrosomonas., (ii) Nitrifying Bacteria—Nitrobacter, 12. Refer to page no. 203., 13. Enzyme-Nitrogenase, Pink coloured pigment-Leghaemoglobin, Mineral Nutrition, , 129
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Short Answers-II, , (3 marks each), , 14. Refer to ‘Points to Remember’., 15. Refer to ‘Points to Remember’., 16. Refer to ‘Points to Remember’., 17. Refer to ‘Points to Remember’ (Fate of Ammonia), 18. Refer to ‘Points to Remember’., 19. Refer to ‘Points to Remember’., , Long Answers, , (5 marks each), , 20. Refer to ‘Points to Remember’., 21. Refer to ‘Points to Remember’., 22. Refer to NCERT Book Page No. 203., , , 130, , Biology Class - 11
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Higher Plants, Points To Remember, Photosynthesis : Photosynthesis is an enzyme regulated anabolic process of, manufacture of organic compounds inside the chlorophyll containing cells from, carbon dioxide and water with the help of sunlight as a source of energy., Sun Light, ↑, , Historical Perspective, Josheph Priestley (1770) : Showed that plants have the ability to take up, CO2 from atmosphere and release O2. (Candle with bell jar and mouse expt.), Jan Ingenhousz (1779) : Release of O2 by plants was possible only in sunlight and only by the green parts of plants. (Expt. with aquatic plant in light & dark), Theodore de Saussure (1804) : Water is an essential requirement for, photosynthesis to occur., Julius Von Sachs (1854) : Green parts in plant produce glucose which is, stored as starch., T.W. Engelmann (1888) : The effect of different wavelength of light on, photosynthesis and plotted the first action spectrum of photosynthesis., C.B. Van Niel (1931) : Photosynthesis is essentially a light dependent, reaction in which hydrogen from an oxidisable compound reduces CO2 to form, sugar. He gave a simplified chemical equation of photosynthesis., Hill (1937) : Evolution of oxygen occurs in light reaction., Calvin (1954-55) : Traced the pathway of carbon fixation., Hatch.and Slack (1965) : Discovered C4 pathway of CO2 fixation., Photosynthesis in Higher Plants, , 131
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Site for photosynthesis : Photosynthesis takes place only in green parts of, the plant, mostly in leaves. Within a leaf, photosynthesis occurs in mesophyll cells, which contain the chloroplasts. Chloroplasts are the actual sites for photosynthesis., The thylakoids in chloroplast contain most of pigments required for capturing solar, energy to initiate photosynthesis : The membrane system (grana) is responsible for, trapping the light energy and for the synthesis of ATP and NADPH. Biosynthetic, phase (dark reaction) is carried in stroma., (Refer figure 13.2, Page 209, NCERT Text Book of Biology, Class XI), Importance of Photosynthesis—(1) Synthesis of organic compounds (2), Change of radiant energy into chemical energy (3) Useful products are obtained, from plants gums, oils timber fire wood, resins rubber, fibers and drugs, etc. (4), Balance the percentage of O2 and CO2 in atmosphere (5) Fossil fuels like coal,, natural gas and petroleum have been formed inside the earth indirectly as a product, of photosynthesis., , Pigments involved in photosynthesis :, Chlorophyll a : (Bright or blue green in chromatograph). Major pigment,, act as reaction centre, involved in trapping and converting light into chemical, energy. It is called universal photo-synthetic pigment., Chlorophyll b : (Yellow green), Xahthophylls : (Yellow), Carotenoids : (Yellow to yellow-orange), , , In the blue and red regions of spectrum shows higher rate of photosynthesis., , Light Harvesting Complexes (LHC) : The light harvesting complexes are, made up of hundreds of pigment molecules bound to protein within the photosystem, I (PS-I) and photosystem II (PS-II). Each photosystem has all the pigments except, one molecule of chlorophyll ‘a’ forming a light harvesting system (antennae). The, reaction centre (chlorophyll a) is different in both the photosystems. (Refer fig., 13.4, Page 211, NCERT-Biology)., 132, , Biology Class - 11
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Light Harvesting Complex, Photosystem I (PS-I) : Chlorophyll ‘a’ has an absorption peak at 700 nm, (P700)., Photosystem II (PS-II) : Chlorophyll ‘a’ has absorption peak at 680 nm, (P680),, Process of photosynthesis : It includes two phases-Photochemical phase, and biosynthetic phase. (Formerly known as Light reaction and dark reaction), (i) Photochemical phase (Light reaction) : This phase includes-light, absorption, splitting of water, oxygen release and formation of ATP and NADPH., It occurs in grana region of chloroplast., (ii) Biosynthetic phase (Dark reaction) : It is light independent phase,, synthesis of food material (sugars). (Calvin cycle). It occurs in stroma region of, chloroplast., Photophosphorylation : The process of formation of high-energy chemicals, (ATP and NADPH) in presence of light., Non-Cyclic photophosphorylation : Two photosystems work in series–First, PSII and then PSI. These two photosystems are connected through an electron, transport chain (Z. Scheme). Both ATP and NADPH + H+ are synthesised by this, process. PSI and PSII are found in lamellae of grana, hence this process is carried, here. (Fig. 13.6) Page 213, NCERT-BIOLOGY. Class-XI., Photosynthesis in Higher Plants, , 133
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Cyclic photophosphorylation : Only PS-I works, the electron circulates, within the photosystem. It happens in the stroma lamellae (possible location), because in this region PSII and NADP reductase enzyme are absent. Hence only, ATP molecules are synthesised. It occurs when only light of wavelengths beyond, 680 nm are available for excitation., The electron transport (Z-Scheme) : In PS II, reaction centre (chlorophyll, a) absorbs 680 nm wavelength of red light which make the electrons to become, excited. These electrons are taken up by the electron acceptor that passes them to, an electron transport system (ETS) consisting of cytochromes. The movement of, electron is down hill. Then, the electron pass to PS I and move down hill further., (Fig. 13.5) Page 212, NCERT-BIOLOGY-Class XI, The splitting of water : It is linked to PS II. Water splits into H+, [O] and, electrons., 2H2O → 4H+ + O2 + 4e–, Chemiosmotic Hypothesis : Chemiosmotic hypothesis explain the, mechanism of ATP synthesis in chloroplast. In photosynthesis, ATP synthesis, is linked to development of a proton gradient across a membrane. The protons, are accumulated inside of membrane of thylakoids (in lumen). ATPase enzyme, has a channel of that allow diffusion of protons back across the membrane. This, release energy to activate ATPase enzyme that catalyses the formation of ATP., (Fig. 13.7). Page 214, , 134, , Biology Class - 11
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6CO2 + 6PEP + 6RuBP + 30ATP + 12NADPH +12H+ Enzymes, C6H12O6 + 6PEP + 6RuBP + 30ADP + 12NADP+ + 3OH3PO4, Photorespiration : The light induced respiration in green plants is called, photorespiration. In C3 plants some O2 binds with RuBisCO and hence CO2 fixation, is decreased. In this process RuBP instead of being converted to 2 molecules of, PGA binds with O2 to form one molecule of PGA and phosphoglycerate., There is neither synthesis of ATP nor NADPH2 or sugar. There is 25% loss, of fixed CO2 so it is wasteful process., , C4 Plants :, , (1) Lack Photorespiration, (2) Show response to high light intensities, (3) Have greater productivity of biomass., , Adaptations in C4 Plants :, , (i) Kranz Anatomy, (ii) Occurrence of two types of cells, (iii) Dimorphic chloroplast, (iv) Presence of RuBisCO in Bundle Sheath cells and PEPase in mesophyll, cells., (v) Mechanism to increase CO2 concentration near RuBisCO in Bundle, Sheath cells., CAM (Crassulacean Acid Metabolism) Plants—Stomata open at night. e.g.,, Cacti, Bryophyllum, Pineapple., Law of Limiting Factors : If a chemical process is affected by more than, one factor, then its rate will be determined by the factor which is nearest to its, minimal value. It is the factor which directly affects the process if its quantity is, changed Factors affecting photosynthesis :, 1. Light : Rate of photo-synthesis increases at low light intensities. At high, intensities of light beyond a point the rate of CO2 fixation decreases. Longer, hours of light duration favour more photosynthesis rate., 2. Carbon dioxide : Increase in CO2 concentration causes increases in CO2, fixation. It is the major limiting factor for photosynthesis., 3. Temperature : The rate of photosynthesis at optimum temperature is, high., It is 20°C-25°C For C3 plants and 30-45°C for C4 plants., 136, , Biology Class - 11
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4. Water : Water is one of the reactant in photosynthesis, but it effects the rate, of CO2 fixation. Low water content causes the stomata to close and reduces, the CO2 availability., , Questions, Very Short Answer Questions, , (1 marks each), , 1. Name two photosynthetic pigments belonging to Carotenoids :, 2. How many molecules of ATP are required for synthesis of one molecule of, glucose in C3 and C4 pathways ?, 3. What part of sunlight is most suitable for photosynthesis ?, 4. Which one of the photosystems can carry on photophosphorylation, independently ?, 5. Name two plants that can carry out photosynthesis at night., 6. Name the most abundant enzyme found in the world., 7. Name the scientist who proposed the C4 pathway. Name one such plants., 8. Where does carbon fixation occur in chloroplast ?, 9. Which compound acts as CO2 acceptor in Calvin cycle ?, 10. Name the end products of light reaction., 11. Does the photosynthesis occur in moon light ? Why ?, , Short Answer Questions-I , , (2 marks each), , 12. Why does the rate of photosynthesis decline in the presence of continuous, light ?, 13. Why do green plants start evolving carbon dioxide instead of oxygen on a, hot sunny day ?, 14. Fill in the space, left blank in the given table to bring the difference between, C3 and C4 plants :, S.No., , Characteristics, , C3 plants, , 1., Cell type, mesophyll, , ...(b)..., 2., CO2 acceptor, 3-PGA, 3., First CO2 fixation, , product, 4., Optimum, ...(d)..., , temperature, , C4 plants, ...(a)... and mesophyll, Phosphoenol, pyruvate (PEP), ...(c)..., 30° C to 45° C, , Photosynthesis in Higher Plants, , 137
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15. State two functions of accessory pigments, found in thylakoids., 16. Why do C4 plants are more expensive (in energy requirement) than C3, plants ?, 17. What is limiting factor ? State the law of limiting factors., , Short Answer Questions-II , , (3 marks each), , 18. The figure shows the effect of light on the rate of photosynthesis. Based on, the graph, answer the following questions :, (i) At which point(s) A, B or C in the curve, light is a limiting factor ?, (ii) What could be the limiting factor(s) in region A ?, (iii) What do region C and D represent on the curve ?, , 19. When and why does photorespiration take place in plants ? How does this, process result in a loss to the plant ?, 20. What are the steps that are common to C3 and C4 photosynthesis ?, 21. Two potted plants were kept in an oxygen free environment in transparent, containers, one in total darkness and the other in sunlight. Which one of the, two is likely to survive more ? Justify your answer by giving the reason., 22. (a) In the diagram shown below, label A, B and C. What type of, phosphorylation is possible in this ?, , (b) Give any two points of difference between cyclic and non-cyclic, photophosphorylation., 138, , Biology Class - 11
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23. Name the pigment found in tomato, carrots, chillies etc. which gives red, colour to them. Is it a photosynthetic pigment ?, 24. Chloroplast and mitochondria are believed to be semi-autonomous organelles., Justify the statement., 25. Mention the conditions under which the C4 plants are superior to C3 plants., , Long Answer Questions, , (5 marks each), , 26. Describe C4 pathway in a paddy plant. How is this pathway an adaptive, advantage to the plant ?, 27. Explain, the process, of biosynthetic plase of photosynthesis occurring in, chloroplast., 28. (a) Give steps to ATP synthesis in chloroplasts through chemiosmosis., (b) Schematically represent non-cyclic photophosphoryation in plants., , Answers, Very Short Answer , , (1 mark each), , 1. Carotene and Xanthophyll., 2. In C3 pathway = 18 ATP molecules In C4 pathway = 30 ATP molecules, 3. Blue and red regions of the light spectrum are the most effective in, photosynthesis., 4. PS-I., 5. Opuntia, Chenopodium, Bougainvillea., 6. RuBisCO., 7. Hatch and Slack. Maize and Sorghum., 8. Carbon fixation takes place in stroma., 9. Ribulose 1, 5 bisphosphate., 10. ATP, NADPH and O2., 11. No, the moonlight is unable to perform light reactions of photosynthesis, (ATP-NADPH Synthesis as it is 1/50,000 the intensity of sunlight and not, strong enough to enable plants to photsynthesise., , Short Answers-I, , (2 marks each), , 12. Increase incident light beyond a point causes the breakdown of chlorophyll., 13. On a hot suny day, enzyme RuBP carboxylase becomes active and its, affinity for CO2 decreases and for O2 increases. Consequently more and, more photosynthetically fixed carbon is lost by photorespiration., Photosynthesis in Higher Plants, , 139
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14. (a) Bundle sheath, (b) RuBP, (c) OAA (oxaloacetic acid), (d) 20°C-25°C, 15. (a) Absorption of light and transfer of energy to chlorophyll ‘a’., (b) Protect chlorophyll ‘a’ from photo oxidation., 16. Because they require more energy (30 ATPs) in synthesizing one glucose, molecule as compared to C3—(18ATPs)., 17. Limiting Factor—A factor which is deficient to such an extent that increase, in its concentration directly increase the rate of the process., (For the law of limiting factors see text in NCERT Book.) Page 222, , Short Answers-II , , (3 marks each), , 18. (i) ‘B’, (ii) CO2 and temperature, , (iii) ‘C’ represents to constant rate of photosynthesis, ‘D’ is the light saturation, intensify at which rate of photosynthesis is maximum., 19. Refer Page no. 220, NCERT, Text Book Biology for class XI., 20. Hints :, , (a) Photolysis of H2O and photophosphorylation occurs in both C3 and C4, plants., (b) In both, dark reaction occurs in stroma., (c) Calvin cycle results in the formation of starch in both the plants., (d) During dark reaction both types of plants undergo the phases of, carboxylation and regeneration :, 21. Hints :, , , The plant in sunlight will survive for longer period., , , Light is essential for photosynthesis., 22. (a) (A) e– acceptor, , , (B) Electron transport system, , , , (C) Chlorophyll P700, , (b) Refer A Page no. 212, NCERT Text Book of Biology for Class XI., 23. Carotenoid : It is an accessory photosynthetic pigment which takes part in, harvesting light energy only if chlorophyll is present., 140, , Biology Class - 11
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24. Mitochondria and chloroplast both contain DNA and can reproduce, independently of the cell and chloroplasts even have a built in feeding, mechanism both have their own ribosomes of 70S type and capable of, synthesising their own kind of proteins., 25. C4 Plant grow in regions with high temperatures and intense light. The rate, of transpiration in C4 plant is 25% of a C3 plant, thus they conserve water, and have greater photosynthetic rate gives greater rate of growth in intense, sunshine and high temperature., , Long Answers, , (5 marks each), , 26. Refer Page no. 218, NCERT Text Book of Biology for Class XI., 27. Refer Points to Remember., , Hints : Three stages of Calvin cycle : Carboxylation, Reduction and, Regeneration., 28. (a) Refer Page no. 213 (Chemiosmotic Hypothesis), NCERT Text Book of, Biology for Class XI., (b) Refer Fig. 13.5 (Z-Scheme of light reaction), NCERT Text Book of, Biology for Class XI., , , Photosynthesis in Higher Plants, , 141
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Points To Remember, Aerobic respiration : Complete oxidation of organic food in presence of, oxygen thereby producing CO2, water and energy., Anaerobic respiration : Incomplete breakdown of organic food to liberate, energy in the absence of oxygen., ATP Synthetase : An enzyme complex that catalysis synthesis of ATP during, oxidative phosphorylation., Biological oxidation : Oxidation in a series of reaction inside a cell., Cytochromes : A group of iron containing compounds of electron transport, system present in inner wall of mitochondria., Dehydrogenase : Enzyme that catalyses removal of H atom from the, substrate., Electron acceptor : Organic compound which receive electrons produced, during oxidation-reduction reactions., Electron transport : Movement of electron from substrate to oxygen through, respiratory chain during respiration., Fermentation : Breakdown of organic substance that takes place in certain, microbe like yeast under anaerobic condition with the production of CO2 and, ethanol., Glycolysis : Enzymatic breakdown of glucose into pyruvic acid that occurs, in the cytoplasm., Oxidative phosphorylation : Process of formation of ATP from ADP and, Pi using the energy from proton gradient., Respriation : Biochemical oxidation food to release energy., Respiratory Quotient : The ratio of the volume of CO2 produced to the, volume of oxygen consumed., Proton gradient : Difference in proton concentration across the tissue, membrane., 142, , Biology Class - 11
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A. Glycolysis : The term has origianted from the Greek word, glycos =, glucose, lysis = splitting, or breakdown means breakdown of glucose molecule, to pyruvic acid. It was given by Embden Meyerhof and Parnas. It is a chainof, 10 reactions to convert glucose into pyruvate. It is common for acerobic and, anaerdomic respiration., , Steps for Glycolysis—(EMP Pathway), 1., 2., 3., , 4., 5., 6., 7., 8., 9., 10., , Phosphorylation of Glucose into Glucose-6-phosphate, Isomerisation of Glucose-6-Phosphate into fractose-6-phosphate, Second phosphorylation in which Fructose-6-phosphate changes into Fructose-1,, 6-biphosphate, Splitting of Fructiose-1, 6-biphosphate into DiHAP and PGAL, Isomerisation of DiHAP into PGAL, Oxidation of PGAL into 1, 3-biphosphosphoglycerate, Synthesis of ATP and converssion of 1, 3-biphosphoglycerate into 3-phospholycerate, Isomerisation of 3-phosphoglycerate into 2-phospholycerate, Dehydration of 2-phosphoglycerate into PEP, Substrate level ATP synthesis and formation of Pyruvic Acid., , , , , , , , , , , It is also called Embden—Meyerhof—Paranas pathway. (EMP pathway), It is common in both aerobic and anaerobic respiration., It takes palce outside the mitochondria, in the cytoplasm., One molecule of glucose (Hexose sugar) ultimately produces two molecules, of pyruvic acid through glycolysis.’, , During this process 4 molecules of ATP are produced while 2 molecules, , ATP are utilised. Thus net gain of ATP is of 2 molecules., , Input and Output of glycolysis, S. No., , Input, , Output, , 1., , Glucose (6—C) —1, , Pyruvate (3—C) 2 molecules, , , , molecule, , 2., , 2 ATP, , 2 ADP, , 3., , 4 ADP + 2 Pi, , 4., , 2 NAD+, , 4 ADP + 2H2O, 2 NADH (H+), , Net out put ...... 2 Pyruvate + 2ATP + 2NADH (+ H+) OR 2 Pyruvate + 8 ATP, , The pyruvate, so produced, may under go (i) Lactic acid fermentation,, Alcoholic fermentation of Aerobic Respiration (Krebs Cycle), B. Oxidative decarboxylation : Pyruvic acid is converted into Acetyle CoA, in presence of pyruvate dehydrogenase complex., 144, , Biology Class - 11
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Pyruvic acid + CoA + NAD +, , Acetyle CoA + CO2 + NADH + H+, , The Acetyle CoA enters in TCA cycle., C. Tri Carboxylic Acid Cycle (Kereb’s cycle) or Citric acid Cycle : This, cycle starts with condensation of acetyle group with oxaloacitic acid and, water t o yield citric acid which under goes a series of reactions., , , It is aerobic and takes a place in mitochondrial matrix., , , Each pyruvic acid molecule produces 4 NADH + H+, one FADH2, one, ATP., , , One glucose molecule has been broken down t o release CO2 and eight, molecules of NADH + H+, two molecules of FADH2 and 2 molecules, of ATP., , Compensation Point : It is the value of a factor at which the rate of, photosynthesis controlled by it is just equal to the rate of respiration and, photorespiration so that there is not net exchcange of gases between the, phtosynthetic organ and the environment., At compensation point the photosynthetic tissue manufacture only such, amount of food which of sufficient for it to remain alive. No food is supplied, to rest of the plant. Therefore, net photosynthesis is zero., (D) Oxidative Phosphorylation, , The synthesis of ATP from ADP and inorganic phosphate using energy from, proton gradient is called oxidative phosphorylation. This takes place in, elementry particles present on the inner membrane of cristae of mitochondria., This process in mitochondria is catalysed by ATP synthestase (complex V)., This compmlex has two major components F0 and and F1, F0 acts a channel, for proton and F1 acts as an ATP synthetase., , Electron Transport System and Oxidative Phosphorylation, Name of Complex , Complex I, Complex II, Complex III, Complex IV, Complex V, , Components of ETS, , FMN and Fe-S are prosthetic groups and NADH, dehydrogenase, FADH2 dehydrogenase (succinate dehydrogenase), Fe-S,, UQ, Cytochrome bc, complex–cytochrome b, cytochrome C,, Fe-S, UQ, Cytochrome Coxidase–Cytochrome a1, cytochrome a3 which, posses two copper centres., F0–F1 particles Flow of protein through F0 channel induces, F1 partcile to function as ATP synthatase., Respiration in Plants, , 145
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Respiratory Balance Sheet :, glucose + 6O2 + 36ADP + 36Pi → 6CO2 + 6H2O + 36 ATP, Total ATP Production, , Process, , Total ATP produced, , 1. Glycolysis, 2. Oxidative decarboxylation, 3. Kreb’s Cycle, , , 2ATP + 2NADH2 (6ATP) = 8ATP, 2NADH2 (6ATP) = 6ATP, 2GTP (2ATP) + 6NADH2 (18ATP), + 2FADH2 (4ATP) = 24 ATP, , ATP, , Energy production in prokaryotes during aerobic respiration = 38 ATP, Energy poroduction in eukaryotes during aerobic respiration = 38 – 2 = 36, , In eukaryotes 2 ATP are used in transporting 2 molucules of NADH + H+, formed in glycolysis from cytoplasm to mitochandria for oxidation through ETS, shuttle., (2) Anaerobic Respiration—In anaerobic respiration, Glycolysis is followed, by formation of ethanol or lactic acid in the cytoplasm., Fermentation : It is the process of anaerobic respiration which occurs in, yeast and some bacteria. Fermentation involves incomplete oxidation of food into, enthanol and carbon-dio-oxide. It results in the production of 2 ATP molcules., , (i) Conversion of Acetyl CoA into fatty acid and PGA., (ii) Synthesis of chlorophyll and cytochromes from Succinyl CoA, (iii) Synthesis of Amino acids from OAA and α-ketoglutaric acid, (iv) Synthesis of Alkaloid from OAA., Enzymes involved-Pyruvic acid decarboxylase, Alcohol dehydrogenase, Anaerobic respiration in muslces : During vigrous exercise a person feels, pain and fatigue in his muscles. This is due to accumulation of lactic acid in, muscles. When oxygen is inadequate pyruvic acid is reduced to lactic acid in, presence of enzyne-lactic dehydrogenase., , During rest lactic acid is reconverted to pyruvic acid., 146, , Biology Class - 11
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Amphibolic Pathway :, During the process of cellular respiration Carbohydrates, fats and protiens, are broken down to release energy and hence respiration is a catabolic process/, catabolic pathway. From this pathway many compound are withdrawn for synthesis, of substrates. Some anabolic processes are formation of pyruvic acid from amino, acids, and formation of Acetyl CoA from Fatty acid. So—Respiratory pathway is, involved in both catabolism and anabolism, it is better to consider the respiratory, pathway as an amphibalic pathway., , RQ (Respiratory quotient), (a) RQ = 1 (When carbohydrate is used as substrate), C6H12O6 + 6O2 → 6CO2 + 6 H2O + Energy, (b) RQ is less than 1 (i.e., < 1) for fats., 2C51H98O6 + 145O2 → 102CO2 + 98 H2O + Energy, R.Q. ⇒, , = 0.7, , (c) RQ is 0.9 for proteins., (d) RQ is more than 1 (i.e., > 1) for organic acids., (e) RQ is inifinite in case of anerobic respiration, because CO2 is evolved but, O2 is not consumed., , Questions, Very Short Answer Question, , (1 mark each), , 1. Name the molecule which is terminal acceptor of electron., 2. How many ATP molecules are produced from a molecule of glucose on it, complete oxidation in eukaryotes ?, 3. Where does ETC found in eukaryotic cell ?, 4. Name the enzyme which convert sugar into glucose and fructose., 5. How many molecules of ATP are produced by the oxidation of one molecule, of FADH2 ?, 6. Why do the person with sufficient white fibres get fatigued in a short, period ?, 7. Write the name of end product of glycolysis., 8. Name the first product formed in Kreb’s cycle., 9. Define the term ‘Respiratory substrate’., Respiration in Plants, , 147
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10. Which intermediate undergoes lysis in glycolysis ?, 11. Write the other two names of Krebs cycle., 12. Name the acceptor molecule of Krebs cycle., 13. Name the substrate entrant of Krebs cycle., 14. Name the first chemical produced in Krebs cycle., 15. What is Electron Transport Chain ? (ETC)., 16. F0–F1 Protein complexes participate in the synthesis of .........., , Short Answer Questions-I , , (2 mark each), , 17. Differentiate between aerobic respiration and anerobic respiration., 18. Mention two steps of glycolysis in which ATP is utilised., 19. Why does anaeriobic respiration produces less energy than aerobic respiration?, 20. Define Respiration Quotient. What is its value for fat and protein ?, 21. Distinguish between glycolysis and fermentation., 22. What are respiratory substrates ? Name the most common respiratory, substrate., , Short Answer Questions-II, , (3 marks each), , 23. Pyruvic acid is the end product of glycolysis. What are the three metabolic, fates of pyruvic acid under aerobic and anaerobic conditions ?, 24. Give the schematic representation of an overall view of TCA cycle., 25. Where does electron transport system operative in mitochondria ? Explain, the system giving the role of oxygen ?, 26. Give a brief account of ATP molecules produced in aerobic respiration in, eukaryotes., 27. Discuss the respiratory pathway is an amphibolic pathway., 28. Exapnd ETC., ETS and TCA., , Long Answer Questions, , (5 marks each), , 29. What is glycolysis ? Where does glycolysis takes place in a cell ? Give, schematic representation of glycolysis., , 148, , Biology Class - 11
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Answers, Very Short Answers , , (1 mark each), , 1. Oxygen., 2. 36 ATP., 3. Mitochondrial membrance., 4. Invertase., 5. 2 ATP molecules., 6. due to formation of Lactic acid., 7. Pyruvic acid., 8. Citric acid., 9. The organic substances which is catabolised or brokendown enzymatically, in cellular respiration for releasing energy., 10. Frutosel, 6-bisphosphate., 11. (i) Citric acid cycle (ii) Tricarboxylic acid cycle., 12. Oxaloacetate., 13. Acetyl Co-A., 14. Citrate, 15. See text (Points to remember), 16. ATP, , Short Answers-I, , (2 mark each), , 17. Refer NCERT Text Book Chapter 14 (14.3 and14.4)., 18. (i) Phosphorylation of Glucose into Glucose-6-phosphate., (ii) Phosphorylation of Fructose-6-phosphate into Fructose-1,6-biphosphate., 19. Refer NCERT Text Book Chapter 14, Page 230., 20. Refer NCERT Text Book Page no. 236., 21. Refer NCERT Text Book Page no. 229 and page no. 230., 22. Refer NCERT Tex Book Page no. 227., Respiration in Plants, , 149
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Short Answers-II, , (3 marks each), , 23. (i) Aerobic conditions–CO2 + H2O + Energy, (ii) Anaerobic conditions–(fermentation), (a) In muscles – Lactic acid + Energy, (b) Yeast-Ehtanol + CO2 + Energy, 24. Refer NCERT Text Book Fig. 14.3 Page 232., 25. Refer NCERT Text Book Page no. 232 and page no. 233., 26. Refer notes., 27. Refer NCERT Text Book Page no. 235., 28. Seet text (abbreviations)., , Long Answers, , (5 mark each), , 29. Refer NCERT Text Book Page no. 228 and page no. 229., , , 150, , Biology Class - 11
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Points To Remember, Seed Germination : The seed germinates only when favourable conditions, for growth exists in the environment. In absence of favourable conditions it goes, into a period of suspended growth or rest, called dormancy., Abscission : Shedding of plant organs like leaves, flowers and fruits etc., from the mature plant., Apical dominance : Suppression of the growth of lateral buds in presence, of apical bud., Dormancy : A period of suspended activity and growth usually associated, with low metabolic rate. Some, seeds undergo a period of dormancy and can, germinate only after dormancy period gets over., Phytochrome : A pigment, found in plants which control the light dependent, developmental process., Phytohormone : Chemicals’ secreted by plants in minute quantities which, influence the physiological activities., Sensecene : The last phase of growth when metabolic activities decrease., Vernalisation : A method of promoting flowering by exposing the young, plant to low temperature., Growth : An irreversible permanent increase in size, volume and weight of, an organ or its parts or even of an individual., Quiescence : Non germination of a viable seed due to non-availability of, proper environmental conditions., Vivipary : It is the germination of seed while it is still attached to the parent, plant and is nourished by it. e.g., Rhizophora and Sonneratia. As the germinating, seed forms a seedling. It all down into the mud due to increase in weights. In the, mud, lateral roots develops for anchorage., Heterophylly :Occurrence of more than one type of leaves in plants e.g.,, larkspur, Coriander leaves of Juvenile plant are different in shape from mature, plant., Plant Growth and Development, , 151
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Bolting : Elongation of internodes prior to flowering in plants like Cabbage., Photoperiodism : Response of Plants to relative periods of day/night to, induce flowering., According to duration of exposure of plants to light, plants are divided in, 3 categories :, 1. Long Day Plants (LDP)—Plants which need exposure to light for period, exceeding critical duration e.g., wheat, rice, cucumber., 2. Short Day Plants (SDP)—Plants that need exposure to light for period less, than the critical length e.g., Cabbage., 3. Day Neutral Plants (DNP)—There is no correlation between exposure to, light duration & induction of flowering e.g., Tomato., Abbreviations, IAA, Indole acetic acid, NAA, Napththalene acetic acid, ABA, Abscisic acid, IBA, Indole-3 butyric acid, 2.4D, 2.4 dichlorophenoxy acetic acid, PGR, Plant growth regulator, , , Seed Dormancy, , It is the condition of seed when it is , unable to germinate in spite of the, availability of all environmental conditions suitable for germination. , , Quiescence, The condition of a seed when it is, unable to germinate because the, conditions for germination are not, available., , Measurement of growth : Plant growth can be measured by a variety of, ft parameters like increase in fresh weight, dry weight, length, area, volume and, cell number., Phases of growth : The period of growth is generally divided into three, phases, namely, meristematic, elongation and maturation., (i) Meristematic zone : New cell produced by mitotic division at root-tip and, shoot-tip thereby show increase in size. Cells are rich in protoplasm and, nuclei., (ii) Elongation zone : Zone of elongation lies just behind the meristematic zone, and concerned with enlargement of cells., 152, , Biology Class - 11
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(iii) Maturation zone : The portion lies proximal to the phase of elongation., The cells of this zone attain their maximum size in terms of wall thickning, and protoplasmic modification., Growth rate : The increased growth per unit time is termed as growth rate., The growth rate shows an increase that may be arithmetic or geometrical., Growth, In Arithmetic growth :, , Mathematical expression, L1 = L0 + rt, , Curve, Linear curve, , Only one daughter cell continues L1 = Length at time t, to divide mitotically while other, differentiate and matures., , L0 = Length at time zero, r = growth rate, , Sigmoid Growth Curve, W1 = W0ert, , Sigmoid or, , The initial growth is, , W0 = Initial size, , S-curve, , slow (lag phase) and increase, , W1 = Final Size, , rapidly there-after at an, , r = growth rate, , exponential rate (log phase), , t = time of growth, , In both, the progeny cells divide, , e = base of natural, , Geometrical growth, , mitotically and continue to do so. logarithms, However, with limited nutrient, supply, the growth slow down, leading to stationary phase., Plant Growth and Development, , 153
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Sigmoid growth curve, Lag phase—Growth is slow in initial stage., Log phase : Period of maximum growth, Stationary phase—When the nutrients become limiting, growth slows down., Relative Growth : The growth per unit time as percentage of initial size, RGR =, , × 100, , Differentiation : A biochemical or morphological change in meristemic, cell (at root apex and shoot apex) to differentiate into permanent cell is called, differentiation., Dedifferentiation : The phenomenon of regeneration of permanent tissue, to become meristematic is called dedifferentiation., Redifferentiation : Meristems/tissue are able to produces new cells that, once again lose the capacity to divide but nature to perform specific functions., , Conditions or factors influencing Growth, 1. Nutrition 2. Availability of water 3. Temperature 4. Oxygen 5. Light, 6. Gravity 7. Stress factors like minerals, water or temperature etc., Phytohormone or Plant Growth-Regulator, Growth promoting hormones : These are involved in growth promoting, activities such as cell division, cell enlargement, flowering, fruiting and seed, formation. e.g., Auxin, gibberellins, cytokinis., Growth inhibitor : Involved in growth inhibiting activities such as dormancy, and abscission. e.g., Abscisic acid and Ethylene., Hormones, 1. Auxins (Growth Promoters), e.g.Indole 3-Acetic Acid, [2, 4-D and 2, 4, 5,-T etc.], , Functions, 1. Apical dominance, cell elongation,, Promote flowering prevent premature, leaf and fruit falling, initiate rooting, in stem cutting, as weedicide, induce, parthenocarpy., , 2. Gibberellins (Growth Promoters) 2. Delay senescence, speed up malting, process, increase in length of axis, GA 3 (C19 H 22 O6 , (grape stalk), increase in length of stem, eg. GA 4 , GA 7 , GA19 and , (sugarcane), bolting in beet, cabbages and, , , many plants with rosette habit., GA 20 etc., 154, , Biology Class - 11
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3. Cytokinins (Growth Promoters), e.g. Zeatin (trans 6-purine , DMAA-Dimethylalyl , , , adenine and Isopentyl , , , adenine (IP) etc., , 4. [Ethylene (H2C = CH), A goreous PGR which acts, as Growth Promoters as well, growth inhibitor (mearly as, growth inhibitor), , 5. Abscisic acid (ABA), eg. (Abscisin II Dormin), , 3. Promote cell division, induce cell, enlargement, reduce apical dominance,, induce growth in auxiliary bud, chlorophyll, preservation, lateral shoot growth,, adventitious root formation., , 4. Promotes senescence and abscission of, leaf and fruits, promotes ripening of fruits,, break seed and bud domancy, initiate, germination in peanut, sprouting of potato, tuber, promotes root growth and root hair, formation., 5. Inhibit seed germination, stimulate closer, of stomata, increase tolerance to various, stress, induce dormancy in seed and bud,, promotes ageing of leaf (senescence)., Can delay the ripening of stored fruits as, it absorbs the ethylene., , Questions, Very Short Answer Question, , (1 mark each), , 1., 2., 3., 4., 5., , Write the cause of ‘Bakane’ disease of rice., Name the plant hormone which was first isolated from human urine., Name the only gaseous plant hormone., How does abscisic acid acts as stress hormone in drought condition ?, A farmer observed some broad-leaved weeds in a wheat crop farm. Which, plant hormone would you suggest remove them ?, 6. Name the plant growth regulators you should use to (a) Increase the yield, of sugarcane (b) Promote lateral growth (c) Cause sprouting of potato tuber, (d) Inhibit seed germination., 7. Why do lateral buds start developing into branches when apical bud is, removed ?, 8. Flowering in certain plant occur only when they are exposed to low temperature, for a few weeks. Name this phenomenon., Plant Growth and Development, , 155
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9. Name, the hormone released from over-ripe apples and affects all other, apples in a small wooden box., , Short Answer Question-I, , (2 marks each), , 10. How will you induce lateral branching in a plant which normally does not, produce them ? Give reason., 11. What induces ethylene formation in plants ? Give any two different action, of ethylene on plants., 12. What is meant by abscission ? Name phytohormone involved in it., 13. What is meant by apical dominance ? Which hormone control it ?, 14. Differentiate between photoperiodism and vernalization., 15. Name a hormone which is :, (a) gaseous in nature (b) responsible for photo tropism (c) used for killing, dicot weeds (d) Induces flowering in long day plants., , Short Answer Questions-II, , (3 marks each), , 16. A primary root grows from 5 cm to 19 cm in a week. Calculate the growth, rate and relative growth over the period., 17. Where are the following hormones synthesised in plants (a) IAA (b), Gibberellins (c) cytokinins., 18. What would be expected to happen if :, (a) GA3 is applied to rice seedling., (b) a rotten fruit get mixed with unripe fruits., (c) you forget to add cytokinin to the culture medium., 19. Which growth hormone is responsible for the following :, (a) induce rooting in a twig, (b) quick ripening of a fruit, (c) delay leaf senescence, (d) ‘bolt’ a rosette plant, (e) induce immediate stomatal closure in leaves (f) Induce growth in axillary, buds., 20. Define differentiation, dedifferentiation and redifferentiation., 21. Where are auxins generally produced in a plant ? Name any one naturally, occurring plant auxin and any one synthetic auxin., 156, , Biology Class - 11
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22. Define growth rate. Name two types of growth. Give the shape of curve for, these growth., 23. Mention various parameters taken into consideration for measuring the, growth., , Long Answer Question , , (5 marks each), , 24. In list the five categories of phytohormone. Write atleast two uses of each., , Answers, Very Short Answer , 1., 2., 3., 4., 5., 6., , 7., 8., 9., , (1 mark each), , Gibberalla fujkuroi., Auxin, Ethylene, ABA cause rapid closure of stomata, preventing loss of water by transpiration., 2.4-D, (a) Gibberellin, (b) Cytokinin, (c) Ethylene, (d) Abscisic acid, Due to inhibit activity of Auxin lateral growth starts., Vernalisation, Ethylene, , Short Answers-I, , (2 marks each), , 10. When apical bud is removed, lateral branches are produced. Removal of, apical bud effect the auxin is destroyed inducing the lateral buds to grow, rapidly., 11. Refer NCERT Book Page no. 250., 12. Premature fall of leaf and fruit is called abscission., , Abscisic acid, , 13. Refer NCERT Boof Page no. 250., 14. Refer NCERT Boof Page no. 252., 15. (a) Ethylene C2H2 (b) Auxin (c) 2, 4-D (d) Gibberellin, , Short Answers-II, , (3 marks each), , 16. (a) Growth = 19 – 5 = 14 cm, Period = 7 days, , , Growth rate =, , = 2cm/day, Plant Growth and Development, , 157
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(b) Inititial growth =, , cm, , , , Growth rate per day, , , , Relative growth rate =, , = 2 cm, × 100 = 40%, , 17. (a) 1AA = Shoot apex, (b) Gibberellin – young leaves of buds, root tips, (c) Cytokinins – Root apical meristan, 18. (a) Hyper elongation of intenodes of rice seedlings will occur., (b) Unripe fruit s will lead to early ripening and ultimately it will result in, rottening., (c) Short but formation will not occur., 19. Refer NCERT Book., 20. Refer NCERT Text Book Page no. 245., 21. Refer NCERT Text Book Page no. 248., 22. Refer NCERT Text Book Page no. 242 and 243., 23. Refer NCERT Text Book Page no. 241., , Long Answers, , (5 marks each), , 24. Refer NCERT Text Book Page no. 241-250., , , 158, , Biology Class - 11
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Points To Remember, Digestion : The process in alimentary canal by which the complex food is, converted mechanically and biochemically into simple substances suitable for, absorption and assimilation., Food : A substance which on taken and digested in the body provides, material for growth, repair, energy for reproduction and resistance from disease, or regulation of body processes., Thecodont : The teeth embedded in the sockets of the jaw bone, e.g., in, mammals., Diphyodont : The teeth formed twice in life time e.g., in mammals., Heterodont : An adult human has 32 permanent teeth which are of four, different types., Crown, Root, , Different Types of Teeth, (a), , Canine—for tearing, , (b), , Incisors—for cutting, , (c), , Premolars for grinding, , (d), , Molars for churning and grinding, Digestion and Absorption, , 159
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Dental formula of man :, Permanent Teeth), , , 1, , C, , PM, , M, , 32 = 2 ×, , 2, , 1, , 2, , 3, , Upper Jaw, , , , 2, , 1, , 2, , 3, , Lower Jaw, , PM, , Dental formula of man :, (Milk Teeth), , , 1, , C, , 20 = 2 ×, , 2, , 1, , 2 , , Upper Jaw, , 2, , 1, , 2 , , Lower Jaw, , , , Peristalsis : The involuntary moveent of the gut by which the food bolus, is pushed forward., Deglutition : The process of swallowing of food bolus. It is partly voluntary, and partly involuntary., Ruminants : The herbivours animals (e.g., cow, buffalo etc.) which have, symbiotic bacteria in their rumen of their stomach which synthesize enzymes to, hydrolyse cellulose into monosaccharides., Diarrhoea : The abnormal frequent discharge of semisolid or fluid faecal, matter from the bowel., Vomitting : The ejection of stomach contents through the mouth, caused, by antiperistalsis., Dysentery : Frequent watery stools often with blood and mucus and with, pain, fever and causes dehydration., Chyme : The semifluid mass into which food is converted by gastric secretion, and which passes from the stomach into the small intestine., Gastric : Anything associated with stomach is given a prefix ‘gastric’., Proenzyme : The inactive forms of enzymes., Sphincter : A flap like structure at various junctions of the alimentary canal, which facilities one way traffic in the alimentary canal., Bolus : The masticated food mixed with saliva., 160, , Biology Class - 11
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Hepatic : Anything associated with liver is given a prefix ‘hepatic’., Goblet cells : The cells of intestinal mucosal epithelium which secrete, muscus., Glisson’s capsule : The connective tissue sheath which covers the hepatic, lobules of liver., Hepatic lobules : The structural and functional units of liver containing, hepatic cells which are arranged in the form of cords., Sphincter of Oddi : The sphincter which guard the opening of common, hepatopancretic duct., Villi : The small finger-like folding in the small intestine which increase the, surface area for absorption of digested food., Crypts of Lieberkuhn–pits of intestine, Success entericus—Intestinal juices., , Types of Nutrition, Autotrophic, , Heterotrophic, , Photoautotrophic, , Chemoautrophic, , 1. Saprophytic (e.g., yeast), , (e.g., green plants, , (e.g., Nitrosomonas 2. Holotrophic (e.g., man, lion), , & Euglena etc.), , & Nitrobacter, , 3. Parastic (e.g., Ascaris), , Digestion and Absorption, , 161
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Basic Steps of Holozoic Nutrition :, (1) Ingestion : Intake of food., (2) Digestion : Breaking down of complex organic food materials into simpler,, smaller water soluble molecules., (3) Absorption and assimilation : Absorption of digested food into blood or, lymph and its use in the body cells for synthesis of complex components., (4) Egestion : Elimination of undigested food as faeces :, , Digestive glands : (A) Salivary gland—3 types are (1) Parotid (cheek), (ii) Sublinguals (Below the tongue) (iii) Submaxillary or submandibular, (lower jaw) Secrete saliva which contains ptyalin (Salivary Amylase)., (B) Pancreas : Secretes pancreatic juice., , Malnutrition—When a person is not getting enough food or getting, unbalanced diet., , PEM—Protein Energy Malnutrition, , , Kwashiorkar, , Marasmus, , , The word means ‘rejected child’, Word marasmus means working, away, , It is a disorder found in children, Child remaining under-nourished, 1-5 years of age, where child is suffer from marasmus. Usually, weaned off mother’s milk very early. found in children below the age, of 1 year., , Children get low protein and low, It is caused by deficiency of, carbohydrate diet are affected. protein & carbohydrate both., 162, , Biology Class - 11
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Symptoms, , 1. Stunted growth, 2. Dry & scaly skin, 3. Odema (retention of water in tissues), 4. Match stick lags, 5. Protruted Belly, , , 1., 2., 3., 4., 5., 6., , Low body weight, Wasting of muscles, Prominent ribs, Sunken Eyes, Lean body with thin limbs, Mental retardation, , Cure, , Feeding the child with protein rich, diet , including milk, soyabean, egg etc., , , Child should be given protein, diet, with enough quantity of, carbohydrates & fats., , Calorific Value : Amount of heat energy released by 1 gm of substrate after, complete Oxidation., Calorific value of Carbohydrates is 4.1 k.cal/g, Protein is 5.6 kcal/g, Fats is 9.4 kcal/g (app.), , Questions, Very Short Answer Questions, , (1 mark each), , 1. What do you mean by the term malnutrition ?, 2. Name the hardest substance in the body., 3. What is a lacteal and what is its function ?, 4. Name the small projections, found on the upper surface of tongue., 5. Mention the function of epiglottis., 6. Write the names of major parts of stomach., 7. Name the enzyme that digest fats. Mention the end products of fat digestion., 8. In which part of alimentary canal does absorption of water, simple sugars, and alcohol takes place ?, 9. Why are proteases generally released in inactive form ?, Digestion and Absorption, , 163
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10. Trypsinogen is an inactive enzyme of pancreatic juice. An enzyme,, enterokinase, activates it. Which tissue/cell secrete the enzyme ? How is it, activated ?, 11. What is the role of insulin ?, 12. Name any one country where children affected from PEM are found more., , Short Answer Questions-I , , (2 marks each), , 13. What is emulsification ? Where and how does it occur ?, 14. Name three parts of large intestine. Which vestigial organ arises from the, first part of it ?, 15. Name the gland which perform/acts as exocrine and endocrine. Also name, the product which are secreted by it., 16. The wall of alimentary canal is made up of four layers. Give the names of, these four layers., 17. Hydrochloric acid is found in our stomach. What purpose does it serve in, alimentary canal ?, 18. In which part of the digestive system the absorption of following substances, takes place ?, (a) Certain drugs, (b) Glucose, fructose and fatty acids, (c) Water, some minerals and drugs, (d) Simple sugar and alcohol, 19. Differentiate between chylomicron and micelles., , Short Answer Question-II , , (3 mark each), , 20. In the following diagram of duct system of liver, gallbladder and pancreas, label, a, b, c, d, e and f :, , 164, , Biology Class - 11
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21. Give a diagrammatic representation of transverse section of gut., 22. Draw the sketch of anatomical regions of human stomach and label any four, parts in it., 23. How does the nervous system control the activities of gastro-in-testinal, tract ?, 24. Draw a labelled figure of digestive system of human., 25. Give a summary of cause and symptoms of following disorders of digestive, system :, (a) Jaundice, (b) Vomiting, (c) Diarrhoes, (d) Constipation, (e) Indigestion, 26. Navya likes to eat fast food like burgers and fried food. She often complains, of constipation and abdominal pain. On medical diagnosis her haemoglobin, was also found low., (a) Do you approve her feeding habit ? Why/why not., (b) What can be the cause of Navya’s problem ?, (c) What will you suggest her ?, (d) Which values would you use to convince her to get her condition, cured ?, , Answers, Very Short Answer, , (1 mark each), , 1. The state of health due to improper intake of food or nutrients. It covers both, under nutrition as well as over nutrition., 2. Enamel, 3. Lymph vessel found in villi. They help in absorption of fat globules and then, release them into blood stream., 4. Papillae. Some Papillae have taste buds., 5. Prevention the entry of food into the glottis., 6. Cardia, fundic, pyloric., 7. Lipase, fatty acids and glycerol., Digestion and Absorption, , 165
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8. Stomach, 9. If released in active form, they will start digesting the membrances and, muscular walls of the alimentary canal., 10. Intestinal Mucosa., 11. Metabolism of sugar, 12. Africa, , Short Answer Questions–I , , (2 marks each), , 13. The process of breakdown of large fat droplets into smaller ones. It occurs, in duodenum of small intestine. It is brought about by bile salts through, reduction of surface tension of large fat droplets., 14. Caecum, colon and rectum. Vermiform appendix., 15. Pancreas. Exocrine secretion is pancreatic juice containing enzymes and, exocrirne secretions are hormones : Insulin and glucagon., 16. Serosa, muscularis, submucosa and mucosa., 17. (i) Killing of germs present in food, (ii) Conversion of inactive pepsinogen into active form pepsin., 18. (a) Mouth, (b) Small intestine, (c) Large intestine, (d) Stomach, 19. , , 1., , , 2., , , Chylomicron, , Micelles, , Protein coated water soluble, fat droplets released into the, lymph., In this form fats lipids are put, into circulation, , Formed by combination of fatty acid,, monoglycerides and bile salts., , Short Answers Questions–II, , (3 marks each), , 19., 20., 21., 22., , In this form digested fats are absorbed, in intestinal cells in alimentary canal., , Refer Fig. 16.6, Page no. 261 (NCERT Text Book, XI Biology)., Refer Fig. 16.4, Page no. 260 (NCERT Text Book, XI Biology)., Refer Fig. 16.3, Page no. 259 (NCERT Text Book, XI Biology)., Refer page. 264 (NCERT Text Book, XI Biology)., , 166, , Biology Class - 11
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Long Answers, , (5 marks each), , 23. Refer Fig. 16.1, Page no. 258 (NCERT Text Book, Class XI Biology)., 24. Refer Page no. 265-266 (NCERT Text Book, Class XI Biology)., 25. (a) No, I do not approve her feeding habit as it is unbalanced diet which, can lead to diseases., (b) Malnutrition., (c) To include vegetables and fruit in her diet, to eat balanced diet., (d) Scientific knowledge, caring about others., , , Digestion and Absorption, , 167
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Points To Remember, Breathing : (External respiration) The process of exchange of O2 from the, atmosphere with CO2 produced by the cells., Carbamino haemoglobin : Compound formed in RBCs when CO2 combine, with haemoglobin., Inspiration : Oxygen from fresh air taken by lungs and diffuses into the blood., Expiration : CO2 given up by venous blood in the lungs is sent out to exterior., Respiration : The sum total of physical and chemical processes by which, oxygen and carbohydrates (main food nutrient) etc are assimilated into the system, and the oxidation products like carbon dioxide and water are given off., Diaphragm : A muscular, membranous partition separating the thoracic, cavity from the abdominal cavity., Hypoxia—Shortage of oxygen in tissues., Partial Pressure—The pressure contributed by an individual gas in a mixture, of gases. It is represented as pO2 for oxygen and pCO2 for carbondioxide., Pharynx : The tube or cavity which connects the mouth and nasal passages, with oesophagus. It has three parts (i) Nasopharynx (anterior part) (ii) Oropharynx, (middle part) and (iii) Laryngopharynx (posterior part which continues to larynx), Adam’s Apple : The projection formed by the thyroid cartilage and surrounds, the larynx at the front of the neck., Tidal volume (TV) : volume of air taken in/given out during normal, respiration (500 mL.), Inspiratory Reserve Volume (IRV) : Additional volume of air inspired by a, forcible inspiration. 2500mL to 3000mL., Expiratory Reserve Volume (ERV) : Additional volume of air, a person, can expire by a forcible expiration., (RV) volume of air remaining in the lungs even after a forcible expiration, (1100 mL to 1200 mL), 168, , Biology Class - 11
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PULMONARY CAPACITIES : Use in clinical diagnosis., Inspiratory capacity (IC) = (TV + IRV) Total volume of air a person can, inspire after a normal expiration., Expiratory Capacity—Total Volume of air a parson can expire after a normal, inspiration E.C. = TV + ERV, Functional Residual Capacity—Volume of air that will remain in lungs, after a normal expiration (FRC) = (ERV + RV), Vital Capacity (VC) = (ERV + TV + IRV) or the maximum volume of air, a person can breath out after a forced inspiration., Total Lung Capacity : It includes RV, ERV, TV and IRV or vital capacity, + residual volume., Pulmonary—Anything associated with the lungs is given the prefix, ‘pulmonary’ steps involved in respiration—, (i) Breathing or pulmonary ventilation (intake or atmospheric air and releasing, out CO2 rich alveolar air), (ii) Diffusion of gases (O2 and CO2) across alveolar membrane., (iii) Transport of gases by the blood., (iv) Diffusion of O2 and CO2 between blood and tissues., (v) Utilisation of O2 by the cells for catabolic reactions and resultant release of, CO2., , Breathing and Exchange of Gases, , 169
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Mechanism of Breathing, Inspiration :, If the pressure within the lungs (intrapulmonary pressure) is less than the, atmospheric pressure, i.e., there is negative pressure in the lungs with respect to, the atmospheric pressure., , , The contraction of diagphragm increases the volume of thoracic chamber in, the antero-posterior axis., , , , The contraction of external intercoastals muscles lifts up the ribs and the, sternum causing an increase in the volume of thoracic chamber in the dorso, ventral axis., , , , It causes an increase in pulmonary volume & decrease the intra-pulmonary, pressure to less than the atmospheric pressure., , , , It forces the air out side to move in to the lungs, i.e., inspiration., , Expiration :, Relexation of diaphragm and sternum to their normal positions and reduce, the thoracic and pulmonary volume., , , It increases in intrapulmonary pressure slightly above the atmospheric, pressure., , , , It causes the expulsion of air from the lungs, i.e., expiration., , 170, , Biology Class - 11
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Inspiration, , Expiration, , , Contraction of diaphragm and external, intercostal muscles, , ↓, , Increase in the volume of thoracic, chamber, , ↓, Lungs expand, , ↓, Pressure inside the lungs fall, , ↓, Air rushes into lungs, , Relaxation of diaphragm and sternum, ↓, Decrease in the volume of thoracic, chamber, ↓, Lungs contract, ↓, Pressure inside the lings increase, ↓, Air rushes out of lungs, , Respiratory Tract :, , A pair of external nostrils → nasal chamber through nasal passage →, nasopharynx → glottis → larynx → trachea → Left and right primary, bronchi → secondary and tertiary bronchi → bronchioles → vascularised, bag like structures (alveoli) or air-sacs. Each lung is covered with double, layered membrane known as pleura with pleural fluid between them., , Respiratory organs in animals :, (i), (ii), (iii), (iv), , Protozoans, annelids Frogs—Body surface, Fishes, tadpole stage of frog and many other aquatic animals—Gills, Insects and a few other arthropods—Tracheal tubes, All land vertebrates (amphibians, reptiles, aves and mammal)—Lungs., , Conditions required for cutaneous respiration, Skin should be moist and thin. It should be highly vascularised., , Physiology of Respiration :, (a) Exchange of gases—Diffusion of gases takes place from the region of higher, partial pressure to lower (lesser) partial pressure), (i) pO2 in alveolar air = 104 mm Hg., (ii) pO2 in venous blood = 40 mm Hg., , O2 diffuses from alveoli to venous blood., (iii) pCO2 in venous blood = 45 mm Hg., , pCO2 in alveolar air = 40 mm Hg., , CO2 diffuses from venous blood to alveoli, Breathing and Exchange of Gases, , 171
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Regulation of Respiration, A specialised centre in medulla of brain controls the respiratory rhythm., Another region in the pons region of the brain called pneumotaxic centre, can moderate the functions of respiratory rhythm centre. Neural signal from, pneumotaxic centre can reduce the duration of respiration thereby increasing, the respiratory rate. Chemosensitive area present near the rhythm centre, aortic, arch can sense the change in CO2 & H+ concentration, which in turn send signal, to rhythm centre to make necessary adjustment so that those substances can be, eliminated., , Questions, Very Short Answer Questions , , (1 mark each), , 1. Name the organ in human respiratory system which produces sound., 2. How many oxygen molecules can be carried out by one haemoglobin, molecule., 3. Give the name and function of a fluid filled double membranous layer which, surrounds the lungs., 4. Which organ of our respiratory system acts as primary site of exchange of, gases ?, 5. Cigarette smoking causes emphysema. Give reason., 6. Name the principle or process of exchange of gases., 7. What is the role of oxyhaemoglobin after releasing molecular oxygen in the, tissues ?, 8. Name the muscles which facilitate breathing., 9. How is the entry of food prevented in the respiratory tract ?, 10. About 97% of O2 is transported by RBCs in the blood. How does the remaining, 3% of O2 transported ?, , Short Answer Questions, , (2 marks each), , 11. Draw a labelled diagram of a section of an alveolus with a pulmonary, capillary., 12. Following is the table showing partial pressure (in mm Hg) of oxygen and, carbondioxide) at different parts involved in diffusion in comparison to those, in atmosphere. Fill in the blank – a, b, c and d., Breathing and Exchange of Gases, , 173
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Respiratory Atmospheric Alveoli, gases, air , O2, CO2, , (a), 0.3, , Blood, Blood, (Deoxygenated) (Oxygenated), , 104, (b), , 40, (c), , (d), 40, , Tissue, 40, 45, , 13. Name the organs of respiration in the organisms., (a) Flatworms, , (b) Birds, , (c) Frog, , (d) Cockroach, , 14. What are occupational respiratory disorders ? What are their harmful effects, ? What precautions should a person take to prevent such disorders ?, 15. How is respiration different from breathing ?, , Short Answer Questions-II, , (3 marks each), , 16. Explain the role of neural system in regulation of respiration is human., 17. Explain the neural control of respiration in human., , Long Answer Questions, , (5 marks each), , 18. With the help of labelled diagram explain the structure of human respiratory, system., 19. Explain the mechanism of breathing with the help of labelled diagram, involving both stages—inspiration and expiration., 20. Explain the process of exchange of gases with the help of a diagrammatic, representation in human respiratory system., 21. A NGO has reported about children below the age of 16 years working, in a tobacco factory. On reading this news in paper, what will be your, reaction ? Would you like these children to continue working over there, why/why not ?, , 174, , Biology Class - 11
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Answers, , Very Short Answers , , (1 mark each), , 1. Larynx (Sound box), 2. Four molecules, 3. Pleuron. It reduces the friction and keeps the two pleura together and the, lungs inflated., 4. Alveoli of lungs., 5. Cigarette smoking damages alveolar walls due to alveolar sacs remaining, filled with air leading to decreased respiratory surface for exchange of gases., 6. Diffusion., 7. Amino group of reduced haemoglobin combines with CO2 forming, carbaminohaemoglobin to transport CO2., 8. External and internal intercostals muscles, situated between ribs., 9. During swallowing a cartilaginous flap like structure called epiglottis covers, the glottis and prevents the entry of food into respiratory tract., 10. In simple solution form through plasma., , Short Answers-I, , (2 marks each), , 11. Refer fig 17.4, page 273 (NCERT Text Book Class XI Biology), 12. Refer fig 17.1, page 272 (NCERT Text Book Class XI Biology), 13. (a) Body surface (b) lungs (c) skin and lungs (d) Network of trachea, 14. Refer fig 276 (NCERT Text Book Class XI Biology), 15. Slow oxidation of food to release energy is called respiration while breathing, is a biophysical process which is the first step of respiration., , Breathing and Exchange of Gases, , 175
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Short Answers-II, , (3 marks each), , 16. Refer page 275 (17.5) (NCERT Text Book Class XI Biology), 17. Refer content 17.5 regulation of respiration on page no. 275 (NCERT Text, book XI Biology), , Long Answers-II, , (5 marks each), , 18. Refer content 17.1.1 page 29, diagrams 17.1, page 29 (NCERT Text Book, Class XI Biology), 19. Refer content 17.2 and fig 17.2 page 270–271 (NCERT Text Book Class XI, Biology), 20. Refer content 17.3 and fig 17.3 page 272–273 (NCERT Text Book Class XI, Biology), 21. It is very painful to know about such things prevalent in our society. As a, biologist I know long exposure to tobacco particles in air will give rise to, inflammation leading to fibrosis and thus can damage the lungs severely. So, I would not like the children to continue working over there., , , 176, , Biology Class - 11
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Points To Remember, Blood : A special connective tissue that circulates in principal vascular, system of man and other vertebrates consisting of fluid matrix, plasma and formed, elements., Plasma : (Blood – All blood cells = Plasma) The liquid part of blood which, is straw coloured, viscous fluid and contains about 90-92% of water and 6-8%, proteins., Lymph : A clear yellowish, slightly alkaline, coagulable fluid, containing, white blood cells (Only lymphocytes), a liquid resembling blood plasma., Serum : Blood plasma from which fibrinogen and other clotting factors, have been removed. (Plasma– (fibrinogen & other clotting factor) = blood serum., Heart Beat : The rhythmic contraction and relaxation of the heart, which, includes one systole (contraction phase) and one diastole (relaxation phase) of, the heart. Heart beat count of healthy person is 72 times per minute., Cardiac output : The amount of blood pumped by heart per minute is called, cardiac or heart output. The value of cardiac output of a normal person is about, 72 × 70 = 5040 mL or about 5L per minutes., Electrocardiograph : (ECG) the machine used to record electrocardiogram., Electrocardiogram ECG : The graphic record of the electric current, produced by the excitation of the cardiac muscles. It is composed of a ‘P’ wave,, ‘QRS’ wave. (complex) and ‘T’ wave (Refer fig. 18.3, page 286 (for a standard, ECG) (NCERT class XI Biology), , Diagrammatic presentation of a standard ECG., , Body Fluids and Circulation, , 177
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Name and Number/, Structure, Percentage , , Life Span and, Formation, , Function, , (A) Erythrocytes RBCs, , Red colour, , Formed from birth, , Transport of oxygen, , - 4.5 to 5.5 million, , Circular, biconcave, , onward by red bone, , and some amount, , per cubic millimetre of, , denucleated, elastic, , marrow Life-120 days of carbon dioxide, , blood, , lack of cell organelles excess RBCs are, like ER, ribosomes,, , through haemoglobin, , stored in spleen, , mitochondria etc., (B) Leucocytes, , Colourless rounded, , Formed in red bone, , Acts as soldiers, , (WBCs) 5000-8000, , or irregular,, , marrow, Lymph, , scavenger and some, , per cubic mm of, , nucleated 12 to, , nodes, spleen and, , help in healing, , blood, , 20mm wide, life 1-4, , thymus, , days, (i) Agranulocytes (a), , Large rounded, , Lymph nodes,, , Non Phagocytic, , Lymphocytes 20-45%, , nucleus, 6-10 mm, , spleen, thymus red, , secrete antibodies, , of leucocytes , , bone marrow, life few, , , , days to months or, , , , even years, , (b) Monocytes 6-8%, , Largest of all (12-15, , Red Bone marrow,, , phagocytic, very, , leucocytes,, , mm) bean shaped, , life 10-20 hours, , motiles engulf, , nucleus , , germs, , (a) Eosinophils 2-3%, , bilobed nucleus,, , play role in immunity, , of leucocytes, , granules in cytoplasm life 4 to 8 hrs. in, , (ii) Granulocytes, Red Bone marrow,, , non phagocytic, , blood, (b) Basophils 0-5% of, , Three lobed nucleus, , Red Bone marrow,, , release heparin and, , leucocytes, , (s-shaped), , life 4 to 8 hours in, , histamine, , blood, (c) Neutrophils 60-, , Many lobed nucleus, , Red Bone marrow,, , phogocytic, engulf, , 65% of leucocytes, , fine granules, , life 4 to 8 hours in, , germ and dead cells, , blood, (C) Platelets, , Colourless, rounded, , Red Bone marrow, , thrombocytes, , or oval, or irregular, , worm out ones, , 1,50,000-3,50,000, , non-nucleated, , phagocytized in blood, , mm3 of blood, , fragments, , 178, , Biology Class - 11, , help in blood clotting
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Blood Pressure—The resistance offered by the lumen of the artery to the, flow of Blood., Cardiac Cycle : The rhythmic contraction and dilation of different parts of, heart in one beat., Hypertension : The condition when blood pressure is higher than normal, (120/80 mmHg), Systole : Contraction of heart muscles., Diastole : Relaxation of heart muscles., , Lymph, The colourless mobile fluid connective tissue drains into the lymphatic, capillaries from the intercellular spaces. It is formed by squeezing of blood through, capillaries, within tissues. Its flow is unidirectional i.e., from tissues to heart., Composition :, It is composed of fluid matrix, plasma having only lymphocytes of white, blood corpuscles or leucocytes., Functions :, (i) It drains excess of tissue fluid from extra cellular spaces back into the, blood,, (ii) It contain lymphocytes and antibodies., (iii) It transport digested fats., , }, , Pericardium, , Body Fluids and Circulation, , 179
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, , , , , , , , , , , It is the mesodermally derived organ situated in thoracic cavity in between, the two lungs. Protected by a double membrane covering called Pericardium., Four chambers–two (left and right) atria, and two ventricels (left and right), Inner-artrial septum separates the two atria and inter ventricular septum, separates the two ventricles, while the atria and ventricles are separated by, atrioventricular septum., The valves between right atrium and right ventricle is tricuspid while between, left atrium and ventricle is bicuspid or mitral value., The opening of the right and the left ventricles into the pulmonary artery, and the aorta are guarded by semilunar values., The value allow the flow of blood only in one direction, i.e., from atria to, ventricles and from ventricles to pulmonary artery or aorta., , Functions of Blood, Transport, of food, respiratory gases (O2 and CO2), hormones, metabolic, intermediates, waste products, supply of raw materials, regulation of water balance,, regulation of pH and body temperature, and provides immunity., Blood Clotting, Injured Tissue, Blood Platelets, Releases, Disintegrate, ↓, and release ↓, Thromboplastins, Platelet thromboplastin, Ca++ Proteins, Ca+ Proteins, , ↓ ↓, Thrombokinase, , Inactivates heparin and, catalyses, Ca++, Thrombin, Prothrombin, , ↓ Catalyses, Fibrin, Fibrinogen, Clot or Coagulum), (Fibrin + Blood cells, 180, , Biology Class - 11
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Bipod Groups, Blood Antigen (on Anti body : (in Possible recipients, Group the Surface, plasma), having blood group, , of R.B.Cs) , , Possible donors Remarks, having blood, group, , A, A, Anti B, A, AB, O, A, B, B, Anti A, B, AB, O, B,, AB, A and B, None, AB, O, A, B, AB, , , 0, None, Anti A and anti, O, A, B, AB, O, , , B , , —, —, Universal, recipient, Universal, Donor, , Rh (Rhesus) Group :, Discovered by Landsteiner and Wiener in 1940. The antigen found on the, surface of RBCs. The presence of this antigen is termed as Rh-positive (Rh+) and, its absence as (Rh–). It plays a crucial role in childs birth born out of a marriage, between Rh– woman and Rh+ man, causing to produce anti Rh antibodies., →SAN (Sino-artrial node) : A patch of tissues present in the right upper, corner of the right atrium, acts are pacemaker due to having a unique property, of self exitation., →AVN (Atrio Ventricular Node) : A mass of tissues seen in the lower left, corner of the right atrium close to the atrio-ventricular septum. Fresh wave of, contraction generated here, passes over both the ventricles simultaneously along, the bundle of his., , Heart Valves, Tricuspid Valve : The valves formed of three muscular flaps or cups, which, guard the opening between the right atrium and the right ventricle., , Bicuspid Valve (Mitral Valve) :, The valves which guard the opening between the left atrium and the left, ventricle, made up of two flaps., Semilunar Valves : The valves present at the opening of the right and the, left ventricles and allow the entry of blood into pulmonary artery and the aorta, respectively., Reading of ECG : ‘P’ Wave represents the electrical excitation (or, depolarisation) of the atria and leads to the contraction of both the atria., Body Fluids and Circulation, , 181
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‘QRS’ complex : represents the depolarisation of the ventricles, which, initiates the ventricular contraction., ‘T’ Wave : represents the return of the ventricles from excited to normal, state (repolarisation). The end of T-wave marks the end of sytole., Double circulation : The passage of same blood twice through heart in, order to complete one cycle. eg., (i) The blood pumped by the right ventricle (deoxygenated blood) is transported, through pulmonary artery to lungs where CO2 is exchanged with O2 through, diffusion and returns back to the heart through pulmonary vein. It is called, pulmonary circulation., (ii) The oxygenated blood from left ventricle is transported through aorta to, different body parts (cells and tissues) where O2 is exchanged with CO2, through diffusion and then returned back to the heart through vena-cava. It, is called systemic circulation., , Disorders of circulatory System, Hypertension (High blood Pressure) : It results from narrowing of arterial, lumen and reduced elasticity of arterial walls in old age. It can cause rupturing of, capillaries. It is a silent killer., Coronary Artery Disease : (CAD) Atherosclerosis. The supply of the blood, to heart muscles is affected. It is “caused by deposits of Calcium, fat, cholesterol, and fibrous tissues to make the lumen of arteries narrower., Angina Pectoris : Caused due to arteriosclerosis, when no enough oxygen, is reaching the heart muscle due to which the person experiences acute chest pain., Heart attack : Caused when the heart muscle is suddenly damaged by an, inadequate blood supply., Cardiac arrest : The state in which the heart stops beating., Arteriosclerosis : The state of hardening of arteries and arterioles due, to thickening of the fibrous tissue and consequent loss of elasticity. It causes, hypertension., , Questions, Very Short Answer Questions, , (1 mark each), , 1. Name the instrument used for measuring blood pressure., 2. What is lymph node ?, 3. A cardiologist observed an enlarged QRS wave in the ECG of a patient., What does it indicate ?, 182, , Biology Class - 11
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4., 5., 6., 7., 8., 9., 10., 11., 12., , Name the enzyme that catalyses the formation of carbonic acid in erythrocytes., What is systemic circulation ?, Give two examples of extra-cellular fluids., What name is given to the blood vessels which generally bring blood to an, organ ?, Which adrenal hormone accelerates the heart beat under normal conditions, ?, Name the blood vessel that carries blood from the intestine to liver., Define cardiac cycle., Name the protein found in RBCs., What happens to a person suffering from hemophilia ?, , Short Answer Questions-I, , (2 marks each), , 13. Explain when and how the two sounds of heart are produced., 14. Define joint diastole. What are constituents of the conducting system of, human heart ?, 15. Give the names of various types of formed elements present in the blood., , Short Answer Questions-II, , (3 marks each), , 16. Draw a diagram showing schematic plan of blood circulation in human., 17. Why is the SA node called pacemaker of the heart ? Write its full from., 18. In the following diagram of section of a human heart, label a, b, c, d, e, and f., , 19. What is lymph ? Describe its circulation in brief., 20. What is stroke volume ? What is its relation with cardiac output ?, Body Fluids and Circulation, , 183
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21. A person suffering from fever is advised to take blood test. What may happen, to his WBC count and why ?, , Long Answer Questions, , (5 marks each), , 22. Neena is having blood group A-ve while her husband’s blood group is O +ve., Their first child is having blood gp. A +ve. Her second child was born with, severe anemia and jaundice. What could be the reason ? How this situation, could have been avoided ?, 23. Draw a diagram to show the internal structure of human heart. Lable any, two heart chambers, any two heart valves and chordae tendinae in it., 24. Describe the structure of human heart., 25. What is cardiac cycle ? Describe the event that occur during it., 26. Explain Rh grouping and its incompatibility in humans., , Answers, Very Short Answer , , (1 mark each), , 1. Sphygmomanometer., 2. A lymph node is speicalised structure in lymphatic vessel concerned with, the alteration of foreign bodies by the lymphocytes., 3. QRS waves denotes ventricular contraction of heart which may be normal, or abnormal., 4. Carbonic anhydrase., 5. The kind of blood circulation that is concerned with the supply of oxygenated, blood from the left ventrice to all body parts and return of oxygenated blood, to the right atrium of heart., 6. Interstitial fluid and blood plasma., 7. Afferent blood vessel., 8. Noradrenalin., 9. Hepatic portal vein., 10. A regular sequence of three events (i) auricular systole (ii) ventricular systole, and (iii) Joint diastole during the completion of one heart beat., 184, , Biology Class - 11
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11. Haemoglobin., 12. The person suffering from haemophilia lacks clotting factors in blood, which, result the defective clotting mechanism. In case of injury the person is at a, risk of blood loss., , Short Answer-I , , (2 mark each), , 13. (i) ‘Lubb’ the first second which is low pitched, is caused by the closure, of bicuspid and tricuspid valves., (ii) ‘Dup’ the second sound which is high pitched, is caused by the closure, or semilunar valves., 14. In a cardiac cycle when both atria and ventricles are in a diastole and are, relaxed simultaneously is called a joint diastole., Conducting system constitutes : SA node → AV node → Bundle of His →, Purkinje fibres., 15. Erythrocytes, lymphocytes, monocytes, neutrophils * eosinophils, basophils, and platelets., 16. SA node being self excitatory initiate a wave of contraction in the heart., SA node — Sino–Atrial Node., , Short Answer-II, , (3 marks each), , 17. Refer fig. 18.4, page 287 (NCERT Text Book Class XI-Biology), 18. Refer fig. 18.2, page 283 (NCERT Text Book Class XI-Biology), 19. Refer contend fig. 18.2, page 282 (NCERT Text Book Class XI-Biology), 20. During one cardiac cycle or one heart beat the volume of blood pumped by, the heart is called stroke volume. This is normally 70 mL., In one minute the heart beats about 72 times and the amount of blood pumped, per minute is called cardiac output. This is usually 4900 mL. or 5 litres., 21. The WBC count of this person may show an increase from the normal range., As pathogens may be present in his body, so the body is producing more, WBCs to fight against those pathogens. WBC count is a good tool to asses, the presence of infection in a sick person., Body Fluids and Circulation, , 185
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Long Answer , , (5 marks each), , 22. During her first pregnancy with her first Rh +ve child, her body prepared, antibodies against Rh antigen in her blood. In second pregnancy these Rh, antibodies from mother leaked into the blood of foetus (Rh +ve) and destroyed, foetus RBCs. It was the cause of severe anemia., This situation could have been avoided if she had got herself administered, anti; Rh antibodies immediately after first deliver to kill Rh antibodies., 23. Refer fig. 18.2, page 283 (NCERT Text Book Class XI-Biology), 24. Refer content 18.3.1., page 283 (NCERT Text Book Class XI-Biology), 25. Refer content 18.3.2., page 284 (NCERT Text Book Class XI-Biology), 26. Refer content 18.3.2., page 281 (NCERT Text Book Class XI-Biology), , , 186, , Biology Class - 11
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Points To Remember, Ammonotelism :, The animals which excrete ammonia are called ammonotelic and excretion, of ammonia is known as ammonotelism eg. Amoeba, sycon, hydra, liver fluke,, tapeworm, Leech, Prawn, bony fishes etc., , Ureotelism :, excretion of urea is known as ureotelism and the animals which excrete, urea are ureotelic animals eg. mammals, many terrertrial amphibians and marine, fishes and sting rays etc., , uricotelism :, Excretion of uric-acid is known as uricotelism and the animals are called, uricotelic eg. most insects, land snails, lizards, snakes and birds., , Nephrons :, The structural and functional unit of kidneys. Each kidney contains about, one million of nephrons., , Structure of Nephron :, A nephron consists of Glomerulus, Bowman’s capsule, PCT (Proximal, Convoluted Tubule). JG A (Juxaglomerular Apparatus), DCT (Distal Convoluted, Tubule) and the collecting duct. (Refer fig., 19.3, page 292 (NCERT Text Book, of Biology for Class XI), , Structure of Kidney :, Size 10-12 cm in length, 5-7 cm in width, 2-3 cm thick, average weight, about 120-170 g., The blood vessels, ureter and nerves enter in the kidney through hilum, (a notch)., Excretory Products and their Elimination, , 187
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, , The outer layer of kidney is a tough capsule., , , , The outer zone of kidney is cortex and the inner is medulla., , , , , , The medulla is divided into few conical masses (medullary pyramids), projecting into calyces., The cortex extends between medullary pyramids called columns of Bertini., Refer figure 19.2, page 292 (NCERT—Class XI Biology), , Glomerular Filtration :, The filtration of blood in glomerulus, about 1100-1200 ml of blood is filtered, by the kidney per minute., , Glomerular Filtration Rate (GFR) :, The amount of filtrate formed by the kidney per minute is called GFR. In a, healthy individual it is about, 125 ml/minute, i.e. 180 litres per day., , Types of Nephrons :, (i) Juxtamedullary Nephron—About 15% of total nephrons, Glomeruli are, found in inner region of cortex, large in size, long loop of Henle and found, deep in medulla, associated with vasa recta control plasma volume when, water supply is short., (ii) Cortical Nephron—About 85% of total nephron mainly lie in renal cortex,, glomeruli found in outer cortex, short loop of Henle, extends very little in, medulla. They do not have vasa recta., , Functions of Tubules :, (i) PCT—absorption of all essential nutrients and 70-80% of electrolytes and, water, helps to maintain the pH and ionic balance of body fluids by selective, secretion of H+, ammonia and K+ into filtrate., (ii) Henele’s Loop—reabsorption in this segment is minimum, it plays a, significant role in maintenance of higher molarity of medullary interstitial, fluid., (iii) DCT—conditional reabsorption of Na+ and water takes place here,, reabsorption of HCO3 and selective secretion of H+ and K+ and ammonia, to maintain the pH and sodium-potassium balance in blood., (iv) Collecting duct—Large amount of water is absorbed from this region to, produce concentrated urine, it plays a role in maintenance of pH and ionic, balance of blood by selective secretion of H+ and K+ ions., 188, , Biology Class - 11
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Steps of Urine Formation, 1. Gromerular Filtration—Blood is filtered by glomerulus through three, membranes i.e., endothelium of blood vessel, filtration slits of Bowman’s, capsule and basement membrance between these two layers. This filtration is, called ultrafiltration as all constituents of plasma comes into filterate except, proteins., 2. Reabsorption—90% of filtrate is reabsorbed by the renal tubules by active, or passive mechanism., It is evident by the fact that out of 180L of filtrate formed per day only 1.5, L of urine released., 3. Secretion—Tubular cells secrete H+, K+, ammonia into the urine. It maintains, acid-base balance of body fluids., , Mechanism of concentration of the Filtrate (Countercurrent Mechanism) :, Refer fig 19.6 page 296 (NCERT-Class XI Biology), This mechanism is said to be countercurrent mechanism because the out, flow (in the ascending limb) runs parallel to and in the opposite direction of, the inflow (in the descending limb)., NaCl is transported by the ascending limb of Henle’s loop which is exchanged, with the descending limb of vasa-recta., NaCl is returned to the interstitium by the ascending portion of vasa recta., Henle’s loop and vasarecta as well as the counter current in them help to, maintain an increasing osmolality towards the inner medullary interstitium, i.e., from 300 mosmol/L in cortex to about 1200 mosmol/L in inner medulla., Small amount of urea enter, the thin segment of ascending limb of Henle’s, loop which is transported back to the interstitium by the collecting tubule., This mechanism helps to maintain a concentration gradient in the medullary, tubule interstitium., It helps in an easy passage of water from the collecting tubule to concentrate, the filtrate i.e. urine., Anti Diuretic Hormone (ADH) Controls the urine formation when there, is less blood volume due to excessive loss of fluid from the body, osmareceptors, send the signal to hypothalamus to release ADH which in turn facilitates water, reabsorption thus preventing diuresis (increase in frequency of urination), , , Excretory Products and their Elimination, , 189
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Micturition :, The expulsion of urine from the urinary bladder is called micturition. It is, a reflex process but can be controlled voluntarily up to some extent in grown up, children and adults., The CNS (Central Nervous System) sends the signal which cause the, stretching of the urinary bladder when it gets filled with urine., In response, the stretch receptors on the walls of the bladder sends signals, to the CNS., The CNS passes on motor message to initiate the contraction of smooth, muscles of the bladder and simultaneous relaxation of the urethral sphincter, causing the release of urine., An adult human excretes on an average 1 to 1.5 Litres res of urine per day., On an average 25-30 gram of urea is excreted out per day., , Renin Angiotensin System, , , Fall in GFR, , , , ↓ Renin from JG cells, Angiotensinogen → Angiotensin I → Angiotensin II, , , , ↓ Acts on, , , , Adrenal Cortex, , , , ↓ Secretes aldosterone, , , , Reabsorption from DCT, , , , ↓, , , , Increase in GFR, , Role of other organs in excretion :, , , , , , , , Lungs—removes CO2 (18L/day) and water., Liver—secretes bilirubin, biliverdin etc. helps to eliminate these substances, along. with cholesterol, vitamins, drugs and degraded steroid hormones, through digesive wastes., Sweat and sebaceous glands—These glands of skin help to eliminate small, amount of urea, NaCl and lactic acid etc. through sweat while sebaceous, glands help to eliminate some substances like steroids, hydrocarbons and, waxes through sebum., Saliva—It can help to eliminate small amount of nitrogenous wastes., , 190, , Biology Class - 11
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Disorders of Excretory system :, Uremia—The accumulation of urea in blood due to malfunctioning of kidney., , Hemodialysis—The process; of removal of urea from the blood artificially., In this process the blood from an artery is passed into dialysing unit after, adding an anticoagulant like heparin. The blood passes through coiled, cellophane tube surrounding by dialysing fluid. The nitrogenous wastes, from the concentration gradient and the blood becomes clear. This blood is, pumped back to the body through vein after adding anti-heparin to it., Renal calculi—The format ion of insoluble mass of crystallised salts (oxalates, or phosphates of calcium., Glomerulonephritis—Inflamation of glomeruli of kindney., , , Questions, , Very Short Answer Questions, 1., 2., 3., 4., 5., 6., 7., 8., 9., 10., 11., , (1 marks each), , Which gland secretes sebum ?, One part of loop of Hanle is impermeable to water. Name it., Besides water, name any two contnents of human sweat., Explain the function of vasa rectae., Name two types of nephrons found in human kidney., Define GFR (Glomerular Filtration Rate)., The mechanism of concentration of filtrate is also known as counter current, mechanism. Justify the statement., What is micturition ?, Write the function of hormone ‘renin’ produced by kidney., Name the excretary product of (i) reptiles (ii) Prawns., What is vasa recta ?, , Short Answer Questions-I , , (2 marks each), , 12., , , , , Mark the odd ones is each of the following—, (a) Renal pelvis, medullary pyramid, renal cortex, ureter., (b) Afferent arteriole, Henle’s loop, vasa recta, efferent arteriole., (c) Glomerular filtration, antidiuretic hormone, hypertonic urine, collecting, duct., (d) Proximal convoluted tubule, distal convolated tubule, Henle’s loop, renal corpuscle., Excretory Products and their Elimination, , 191
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13. In the following diagram of longitudinal section of kidney (Fig.–1) identify, and label a, b, c and d respectively., , 14. In the diagram (Fig.-2) showing malpighian body (renal corpuscle) identify, and label p, q, r, s., 15. Name two metabolic disorder which can be diagnosed by analysis of urine., , Short Answer Questions-II, , (3 marks each), , 16. In the following diagram (Fig.-3) showing structure of a nephron label a, b,, c, d, e and f., , 17. Describe the hormonal feed back circuit in controlling the renal functions., 18. Give three points of difference between renin and Renin., 19. What are Ammonotelic, ureotelic and uricotelic animals ? Give an example, of each type of these., 20. Why do urine formation less during summers ?, 192, , Biology Class - 11
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Long Answer Questions, , (5 marks each), , 21. Draw a labelled diagram of human urinary system and write one function, of each adrenal gland, ureter, urinary bladder, kidney and urethra., 22. Describe how urine is formed in the nephron through filtration reabsorption, and secretion., OR, , Explain the steps involved in the process of urine formation., 23. Distinguish between (i) Uricotelism and Ureotelism (ii) Sebum and sweat, (iii) Proximal and distal convoluted tubules (iv) Ascending and descending, limbs of Henle’s loop (v) Cortical and Medullary nephrons., OR, Explain the process of reabsorption and secretion of major substances at, different parts of nephron with the help of schematic diagram., , Answers, Very Short Answer , , (1 mark each), , 1. Sebaceous glands (wax–glands), 2. Ascending limb., 3. Sodium chloride, lactic acid, glucose (any two)., 4. It helps to retain reabsorbed ions and urea in the interstitial fluid of the, medulla, to maintain its high osmotic pressure., 5. (i) Juxta medullary nephron (ii) Cortical nephron, 6. The amount of filtrate formed by the kidney per minute., 7. (in the ascending limb) the out/flow runs parallel to and in the opposite, direction of the inflow in the descending limb., 8. The act of passing out urine from urinary bladder., 9. Renin is used to convert angiotensinogen to angiotensin., 10. (i) Uric acid (ii) Ammonia, 11. Capillary network running parallel to loop of Henle is known as Vasa recta., , Short Answer-I , , (2 marks each), , 12. (a) Ureter (b) Henlp’s loop (c) Glomerular filtration (d) Renal Corpuscle., 13. Refer fig. 19.2, page 292 (NCERT Class XI-Biology), Excretory Products and their Elimination, , 193
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14. Refer fig. 19.4 page 293 (NQERT class XI-Biology), 15. Glycosuria, Ketonuria, , Short Answer-II , , (3 marks each), , 16. Refer fig. 19.3, page 292, (NCERT class XI-Biology), 17. Refer content 19.5, page 297 (NCERT class XI-Biology)., 18., , Rennin , , Renin, , , (i) It is a proteolytic enzyme., , (i) It is a hormone that acts as an enzyme., , (ii) It helps in the digestion of milk, , (ii) It converts the protein angiotensinogen, , , , Protein. into angiotensin, , (iii) It is secreted as an inactive, , , form Prorennin which is, , , , activiated to rennin by HC1., , (iv) Its secretion is stimulated by, , , (iii) It is secreted as renin., , (iv) It secretion is stimulated by a reduction, , food. of Na+ level in tissue fluid. (......... any, , three)., , 19. Refer content given in the beginning of the chapter or NCERT Text Book, page 290 class XI-Biology., 20. Due to sweating in summers blood volume is decreased. ADH is secreted, from hypothalamus which increase reabsorption from D.C. tubules thus, amount of urine is decreased., , Long Answer, , (5 mark each), , 21. Refer fig. 19.1, page 291 and content 19.1 (NCERT Text Book page Class, XII-Biology), 22. Refer content points to remember., 23. Refer the content given in the chapter or NCERT Text Book Class-XI Biology, at pages 290, 298 (19.7), 292 and 293 respectively., 24. Refer content 19.3 and content 19.5 at page 294-295 (NCERT Text Book, Class XI-Biology), , , 194, , Biology Class - 11
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Points To Remember, Arthritis : an inflammatory joint disease characterised by inflammation of, joints., Coccyx : tail bone formed by fusion of four coccygeal vertebrae in man., Dicondylic Skull : A Skull with two occipital condyles., Endo Skeleton : A skeleton present in side the body., Fascicle : Bundles of muscles fibres held together by connective tissue., Fascia : Collagenous connective tissue layer that surrounds muscle bundles., Floating ribs : The ribs that remain free anteriorly, (last 2 pairs), False ribs : 8th, 9th and 10th pair of ribs not directly joins the sternum but, to seventh pair of ribs, hence called pseudoribs., Myoglobin : A red colored pigment present in sarcoplasm of muscle., Sarcomere : A portion of myofibril between two successive ‘Z’ lines., Sarcocolema : The plasma membrane of a muscle., Gout : Inflammation of joints due to accumulation of uric acid crystal., Suture : immovable joints between skull bones., Synovial joints : Freely movable joints between limb bones., Patella : A seasmoid bone acting as kneecap., Intervertebral disc : Fibro cartilaginous pad present between the vertebrae, that act as shock absorbers., Tendon—Connective tissue made of yellow fibrous tissue which connect, muscle to bone. It is not flexible., Ligament—Connective tissue made of white fibrous tissue which joins two, bones. It is flexible., L.M.M. : Light meromyosin, HMM : Heavy meromyosin, Types of Movement :, Locomotion and Movement, , 195
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1. Amoeboid movement : These movements takes place in phagocytes, where leucocytes and macrophages migrate through tissue. It is affected by, pseudepodia formed by the streaming of protoplasm (as in amoeba), 2. Ciliary movement : These movement occurs in internal organs which are, lined by ciliary epithelium., 3. Muscular Movement : This movements involve the muscle fibers, which, have the ability to contract and relex., Properties of Muscle : (i) Excitability, (ii) Contractility, , (iii) Extensibility, (iv) Elasticity, , Types of Muscles :, (a) Skeletal muscles or striated muscles—These involved in locomotion and, change of body postures. These are also known as voluntary muscles., (b) Visceral muscles or smooth muscles—These are located in inner wall of, hollow visceral organ, smooth in appearance and their activity are not under, control of nervous system. They are called involuntary muscles., (c) Cardiac muscles—The muscles of heart, involuntary in nature, striated and, branched, These are uninucleated., Characteristic Skeletal Muscle, , Smooth Muscle, , Cardiac Muscle, , Location, Muscles attached with, , skeletal components, Appearance, Striated having light and, , dark bands., , Control, They are controlled by, , our will hence called, , voluntary muscles, , muscles found in the inner walls of hollow visceral organs, unstriped, smooth in, appearance with tapering, ends, They are not under the, control of our will hence, called involuntary muscles, , Muscles found only, in heart, Striated in, appearance and, branched, not under the, direct control of, nervous system, , Structure of myofibril :, , , , , , , , , , Each myofibril consist of alternate dark and light band., Dark band—contain myosin protein and is called A-band or Anisotroic band., Light band—Contain actin protein and is called I Band or Isotropic band., I Band is bisected by an elastic fiber called ‘Z’ line. Actin filament (thin, filament) are firmly attached to the ‘Z’ lines., Myosin filament (thick filament) in the ‘A’ Band are also held together in, the middle of T Band by thin fibrous membrane called ‘M’ line., The portion between two successive ‘Z’ lines is considered as functional, unit of contraction and is called a sarcomere., , 196, , Biology Class - 11
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Structure of Actin and Myosin Filament, , 1. Actin filament : An actin filament is made of two ‘F’ actins which are, helically wound to each other. Two filaments of tropo myosin protein also, run close to ‘F’ actins throughout its length. A complex protein Troponin is, distributed at regular intervals on tropomyosin which mask the actin binding, site for myosin., 2. Myosin filament : Each myosin filament is a polymer of meromyosin., Each meromyosin has two components—a globular head with a short arm, and a tail. Head is made of heavy meromyosin while tail is made of light, meromyosin. The head with its short arm project outward at regular distance, and angle from each other and is known as cross arm. The head has an active, site for actin and binding site for ATP., , Red muscle fibres :, —, —, —, —, , These are red in colour due to presence of high content of myoglobin., These contain plenty of mitochondria., Sarcoplasmic reticulum is less in these fibres., Show slow but sustained contractions for longer periods., Locomotion and Movement, , 197
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White muscle fibres, — These are pale or whitish due to presence of less content of myoglobin., — These contain fewer mitochondria, — Sarcoplasmic reticulum is more/high, — During strenuous exercise, lactic acid accumulates in large quantity so muscle, fatigues, , Mechanism or Muscle contraction : Sliding filament theory, The contraction of muscle fiber takes place by the sliding of actin (thin, filament) on myosin (thick filament), , , Muscle contraction is initiated by a signal sent by the CNS via a motor, neuron., , , , Impulse from motor nerve stimulates a muscle fiber at neuro muscular, junctions., , , , Neurotransmitter releases here which generates an action potential in, sarcolema., , , , This causes release of Ca++ into sarcoplasm. These Ca++ binds with troponin,, thereby remove masking of active site., , , , Myosin head binds to exposed active site on actin to form a cross bridge,, utilising energy from ATP hydrolysis., , , , This pulls the acin filament towards the centre of ‘A’ band., , , , ‘Z’ lines also pulled inward thereby causing a shortening of sarcomere i.e., contraction., , , , I band get reduced, whereas the ‘A’ band retain the length., , , , During relexation, the cross bridge between the actin and myosin break., Ca++ pumped back to sarcoplasmic cisternae. Actin filament slide out of ‘A, band and length of I band increase. This returns the muscle to its original, state., , 198, , Biology Class - 11
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Vertebral formulae of man C7T12L5S(5) C(4) = 33, Human skeleton – 206 bones, Axial skeleton (80 bones), , skull (29 bones), cranium-8 face-14, Ear ossicle-6, Hyoid-1, , Appendicular, skeleton (126 bones), , vertebrae (26) (33) , 1, Cervical-7, stemum, Ribs, Thoracic-12, 1, 12 pairs (24), Lumber-5, sacral-1 (5-fused to form 1 sacrum), Caudal-1 (4-coccygeal fused to form 1 coccyx), , Girdles (6 bones) , Clavicle 2, Pectoral (Shoulder girdle) , Pelvic (Hip gridle( (2), Scapula-2, Fore limbs (60 bones) - 30 in each limb, Humerus-2 , Radius-2 , Ulna-2 , Carplas-16 , Meta Carpals-10 , Phalanges-28=2× (2, 3, 3, 3, 3) , , Joints, , Fibrous joints, do not allow, movement, , Cartilaginous joints, allo very slight, movement, , e.g., joints between, the bones of skull, , e.g., joint between, adjacent vertebrae, , Limbs (120 bones), , Hind limbs (60) 30 in each limb, Femur-2, Tibia-2, Fibula-2, Patella-2, Tarsals-14, Meta Tarsal-10, Phalanges-28, , Synovial joints, Freely, movable, , Ball and socket, Hinge, Pivot, Gliding, Joints, Joints, Joints, Joints, e.g., between humerus e.g., knee, e.g., Atlas, e.g., between, and pectroal girdle, Joint, and axis, carpals, between femur, Elbow joint , and pelvic girdle, , Saddle, Joints, e.g., between, Carpals and meta, carpals of thumb, , Locomotion and Movement, , 199
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Questions, Very Short Answer Questions, , (1 mark each), , 1. What is the total number of bones present in left pectoral girdle and left arm, respectively in human beings., 2. Why do skeletal muscle show striation., 3. Why are 11th 12th pair of ribs called floating ribs ?, 4. Write the name of chemical that causes fatigue in the muscles., 6. What lubricate the freely movable joints at the shoulder ?, 7. Name of longest bone of human body., 8. Give the name of first vertebra., 9. Define a sarcomere., 10. Name the cup shaped bone that constitutes the knee cap., 11. Which muscle fibre work during long flight of eagle ?, 12. Name the cavity in the girdle into which the head of femur fits ?, , Short Answer Questions-I , , (2 marks each), , 13. Write any two difference between cardiac muscle and skeletal muscle., 14. Distinguish between red fibre and white fiber., 15. Name the two types of girdles found in human body and write their role., 16. State the role of calcium ions and ATP in muscle contraction., 17. Name the bones of fore limb (hand) of human body. Give their number in, each limb., 200, , Biology Class - 11
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Short Answer Questions-II, , (3 marks each), , 18. What makes the synovial joints freely movable ? List any four types of, synovial joints., 19. Name the category of bones forming the ribcage. How are these articulated, to each other to form the cage ?, 20. How are actin and myosin filament arranged in a muscle fibre ?, 21. Mention the factor which is responsible for the following :, (i), , Tetany (ii) Gout (iii) Osteoporosis, , Long Answer Questions, , (5 mark each), , 22. Explain the important steps of sliding filament theory of muscle contraction., , Answers, Very Short Answers, , (1 mark each), , 1. Left pectoral girdle has 2 bones (1 clavicle and 1 scapula). Left Arm has 30, bones., 2. Due to distribution pattern of actin and myosin protein., 3. These ribs are not ventrally attached to sternum, 4. Actin and myosin, 5. Lactic acid, 6. Synovial fluid, 7. Femur, 8. Atlas, Locomotion and Movement, , 201
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9. A portion of myofibril between two successive ‘Z’ lines., 10. Knee cap, 11. Red muscle fibre, 12. Acetabulum, , Short Answers-I, , (2 marks each), , 13. Refer NCERT Text book Class XI Page 303, 14. Refer Points to remember, 15. Refer NCERT Text book Class XI Page 311, 16. Refer NCERT Text book Class XI Page 307 and 308., 17. Refer Points to remember, , Short Answers-II, , (3 marks each), , 18. Refer NCERT Text book Page 312. Class XI, 19. Refer NCERT Text book Page 310. Class XI, 20. Refer NCERT Text book Page 305. Class XI, 21. Refer NCERT Text book Page 312. Class XI, , Long Answer, , (5 marks each), , 21. Refer Points to remember, , , 202, , Biology Class - 11
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Points To Remember, Coordination : Process through which two or more organs interact and, complement the functions of one another surrounding the brain., Action potential : A sudden change in the electrical charges in the plasma, membrane of a nerve fibre., Aqueous humour : The thin watery fluid that occupy space between lens, and cornea in eye., Blind spot : A spot on ratina which is free from rods and cones and lack, the ability for vision., Cerebrospinal fluid : An alkaline fluid present in between inner two layer, of meninges, surrounding the brain and spinal cord., Cerebellum : A part of hind brain that controls the balance and posture of, the body., Cochlea : A spirally coiled part of internal ear which is responsible for, hearing., Corpus callosum : A curved thick bundle of nerve fibres that joins two, cerebral hemisphere., Depolarisation : A condition when polarity of the plasma membrane of, nerve fibre is reversed., Endolymph : The fluid filled within membranous labyrinth., Ecustachian tube : A tube which connect ear cavity with the pharynx., Fovea : An area of highest vision on the ratina which contain only cones., Meninges : Three sheets of covering of connective tissue wrapping the brain., Grey Matter : This shows many convolutions which increase the amount, of vital nerve tissue., Medula oblongata : Posterior most part of the brain which is continuous, with spinal cord and control respiration, heart rate,swallowing,vomiting., Neural Control and Coordination, , 203
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Pons : Thick bundles of fibres on the ventral side of brain below cerebellum., Foramen magnum : A big aperture in the skull posteriorly through which, spinal cord emerges out., Spinal cord : A tubular structure connected with medulla oblongata of brain, and situated in the neural canal of the vertebral column, covered by meninges., Synaptic cleft : A narrow fluid filled space which separates two membranes, of the two neurons at the synapse., Synaptic vesicles : These are membrane bound vesicles in the axoplasm of, the axon terminal and these store neurotransmitter., Neurotransmitter : These are chemicals stored in synaptic vesicles, diffuse, to reach the membrane of next neuron for its stimulation., Synapse : A physiological junction between axon of one neuron and dendrite, of next neuron., CNS—Central neural system, PNS—Peripheral neural system, ANS—Autonomic neural system, Neural System, Central neural System, Brain, , Peripheral neural System, , Spinal cord, , Cranial nerve, , Spinal nerve, , 12 pairs, , 31 pairs, , Nerve fibres of PNS, Afferent fibres Tansmit impulse, from Tissue/organ to CNS, , Efferent fibres Transmit impulse, from CNS to Peripherel tissue/organ, , Division of PNS, Somatic neural System, , Automatic neural system Transmit, , Relays impulse from CNS, , impulse from CNS to involuntary, , to Skeletal muscle, 204, , Biology Class - 11, , Organ and smooth muslces
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Cell body = Cytoplasm with nucleus, cell organelles and, Nissl’s granules, Parts of Neuron, , Dendrites = Short fibres which branch rapidly and project, out of cell, Axon =, , Single, long fibre, branched at distal endit, , (Refer fig. 21.1, page 317, NCERT - Biology, Class-XI), Multipolar = : One axon and two or more dentrites, : Found in cerebral Cortex, Neuron, , Bipolar =, , : One axon and one dendrite, : Found in ratina of eye, , Unipolar = : Cell body with axon only, : Found usually in the embryonic stage, Conduction of nerve impulse along axon, , Polarised membrane/Resting Potential, In resting phase when neuron is not conducting an impulse, the axonal, membrane is called polarised. This is due to difference in concentration of ions, across the axonal membrane., , At Rest :, , , Axoplasm inside the axon contain high conc. of K+ and low conc. of Na+., , , , The fluid outside the axon contain low conc. of K+ and high conc. of Na+., , As a result the outer surface of axonal membrane is positively charged and, inner surface is negatively charged. The electric potential difference across the, resting plasma membrane is called resting potential., Action Potential : When a nerve fibre is stimulated, the permeability of, membrane to Na+ is greatly increased at the point of stimulus (rapid influx of, Na+) and hence polarity of membrane is reversed and now membrane is said to, be depolarised. The electric potential difference across the plasma membrane at, that site is called action potential, which infact termed as nerve impulse., Depolarisation is very rapid, so that conduction of nerve impulse along the, entire length of axon occurs in fractions of second., Neural Control and Coordination, , 205
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Transmission of Impulses at Synapse, (i) At electrical synapses : Here the membrane of pre and post-syneptic neuron, are in very close proximity. Electric current can flow directly from one neuron, into other across these synapses, like impule conduction along a single axon., (ii) At chemical synapses : Here the membrane of pre and post-syneptic neuron, are separated by fluid filled space called synaptic cleft. Neurotransmitter are, involved here., When an impulse arrives at the axon terminal, it stimulates the movement of, the synaptic vesicles towards membrane and they fuse with the plsama membrane, and release their neurotransmitter in the syneptic cleft. These chemicals bind to, specific receptors, present on the post-syneptic membrane. Their binding opens, ion channels and allow the entry of ion which generate new potential in post, synaptic neuron., Human brain : Human brain is the major portion of central neural system., Which is well protected by the skull., The brain is surrounded by three cranial meninges—, (i) Duramater—outer alyer, (ii) Arachnoid—middle layer, (iii) Piamter—Inner layer-remain incontact with brain, Parts of Brain, Fore brain, Mid brain, (a) Cerebrum , (b) Thalamus , (c) Hypothalamus , , Hind brain, (a) Cerebellum, (b) Pons, (c) Medulla oblongata, , Functions of pars of brain :, Cerebrum : Centre of intelligence, memory and imagination, reasoning,, judgement, expression of will power., Thalamus : Acts as relay centre to receive and transmit general sensation, of pain, touch and temperature., Hypothalamus : Centre for regulation of body temperature, urge for eating, and drinking., Midbrain : Responsible to coordinate visual reflexes and auditory reflexes., Cerebellum : Maintains posture and equilibrium of the body as well as, coordinates and regulates voluntary movement., 206, , Biology Class - 11
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Pons : Relays impulses between medulla oblongata and cerebral hemisphere, and between the hemisphere of cerebrum and cerebellum. It also heps to regulate, breathing., Medulla oblongata : Centre that control heart beat, breathing, swallowing,, salivation, sneezing, vomitting and coughing., Reflex action : It is spontaneous, autonomic and mechanical response to, a stimulus that occurs at the level of spinal cord, without involvement of brain., Reflex arc : The flow of nerve along the specific during reflex action. It, consist of—, (a) A receptor, (b) An Afferent neuron (sensory neuron), (c) An inter neuron, (d) An efferent neuron (motor neuron), (e) An effector organ, Sensory neuron, Stimulus, Receptor, (REFLEX - ARC), Inter neuron of spinal cord, Response, Effector organ, motor neuron, Organ of Sight-Eye, Layer, , Component, , Function, , 1. External layer, , Sclera, , Protects and maintain shape of the, , , , eye ball, , , , Outermost transparent portion of, , Cornea, , , , eye which allows light to enter, , 2. Middle layer, , Absorb light and prevent light from, , Choroid, , , , being reflected within the eye ball., , , Ciliary body, , , Holds lens, regulate shape of the, lens., , , , Iris, , Control amount of light entering., , 3. Inner layer, , Retina, , Vision in dim light, colour vision,, , , , , , vision in bright light. Sends the, image to brain through optical, nerves., , (Refer-Fig. 21.6, Page 323 NCERT-Biology, Class XI), Neural Control and Coordination, , 207
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Organ of Hearing–Ear, Portion of the ear Component, Function, 1. External ear, Pinna, Collect sound waves, , External, Direct sound waves towards ear drum,, , auditory canal, ear wax prevents the entry of foreign, , bodies., 2. Middle ear, Tympanic, Acts as resonator that reproduces, , membrane, the vibration of sound., , Ear ossicles, Transmit sound waves to internal ear., , Eustachian tube Helps in equalising the pressure, , on either side of ear drum., 3. Internal ear, Cochlea, Hearing organ., , Vestebular, Balancing of body., , apparatus, (Refer Fig. 21.7, page 325-NCERT-Biology, Class XI), , Questions, Very Short Answer Questions, , (1 mark each), , 1., 2., 3., 4., 5., , Name the fluid present in membranous labyrinth., Name the area of ratina where only cones are densly packed., Name the inner most meninges of the brain., To which part of the brain communication and memory are associated ?, Name the bundle of fibres that connect two cerebral hemisphere in human, being., 6. Name the photo pigment present in the rod cells., 7. Why do impulses flow only in one direction ?, 8. Where is hypothalamus located in the brain ?, 9. Which cells are responsible for scotopic vision ?, , Short Answer Questions-I , 10., 11., 12., 13., 14., , (2 marks each), , Distinguish between electrical synapses and chemical synapses., What is iris ? Give the function of iris., What is organ of corti ? Where is it located ?, Differentiate between cerebrum and cerebellum., What is synapse ? Name its two types., , 208, , Biology Class - 11
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15. Fill in the blanks in the different columns A to D :, Part/Organ, , Function, , , Pinna , ........(A)........., ........(B)........., Equalise the pressure on either side of ear drum., Cone cells, ........(C)........., ........(D)........., regulate amount of light to pass into the eye., 16. why are grey matter and white matter contained in human nervous system, named so ?, , Short Answer Questions-II, , (3 marks each), , 17. Observe the diagram given right and answer the following questions :, , (i), , Label the parts A, B, C & D., , (ii), , Give the function of C and D., , (iii) Name the layers which wrap this organ., 18. What is a synapse ? How does the nerve impulse cross the chemical, synapse ?, 19. Give the function of the following :, (i), , Cerebrum, , (ii) Hypothalamus, , (iii) Mid brain, , 20. What is meant by reflex action ? Name the components of a reflex arc in, correct sequence from receptor upto effector. Support your answer by a, diagram., 21. Draw a diagram of V.S. of human eye and label the following :, Iris, Ratina, Cornea, Blind spot, Ciliary body and Vitreous chamber., Neural Control and Coordination, , 209
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Long Answer Qeustions , , (5 mark each), , 22. Describe in detail, how conduction of never impulse takes place through a, nerve fibre., , Answers, Very Short Answers, 1., 2., 3., 4., 5., 6., 7., 8., 9., , Endolymph, Fovea, Piamater, Cerebrum, Corpus callosum, Rhodopsin, Because each synapse allows impulse to cross it in a single direction., At the base of thalamus., Rods, , Short Answers-I, 10., 11., 12., 13., 14., 15., , 16., , (1 mark each), , (2 marks each), , Refer NCERT text book, Class XI Page no. 319., Refer NCERT Text book, Class XI Page no. 323., Refer NCERT Text book, Class XI Page no. 326., Refer NCERT Text book, Class XI Page no. 321., Junction between two nerves Chemical synapse and electrical synapse, (A) To collect sound waves (B) Eustachina tube, (C) Colour vision , (D) Iris, Refer NCERT book, Page no. 321., , Short Answers-II , , (3 marks each), , 17. (i) A : Cerebrum , C : Cerebellum, B : Corpus callosum , D : Medulla oblongata, (ii) C : Balancing of body and maintain posture, D : Vomiting , coughing, breathing, salivation or any other correct answer, (anyone)., (iii) Pia meter, arachnoid and dura mater., 210, , Biology Class - 11
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18. Refer NCERT Text book, Class XI Page no. 319., 19. Refer NCERT Text book, Class XI Page no. 321., 20. Refer NCERT Text book, Class XI Page no. 322., 21. Refer NCERT Text book, Class XI Page no. 323., , Short Answer, , (5 mark), , 22. Refer NCERT Text book, Class XI Page no. 317 and 318., , , Neural Control and Coordination, , 211
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Points To Remember, Endocrine glands : These are ductless glands which secrete hormones, directly into the blood stream., Hormones : Non-nutrient chemicals synthesised in trace amount by, Endocrine glands that act as intracellular messengers and are specific in their, action., , Hypothalamus :, , , , , , It is basal part of diencephalon., Has neurosecretory cells called nuclei which produce hormones to regulate, the synthesis and secretion of pituitary gland hormones., Two types of hormones released are :, , , Releasing hormones : Simulate secretion of pituitary hormones, e.g.,, Gonadotrophin releasing hormone stimulates pituitary gland to synthesise, gonadotrophins., Inhibiting hormones : Inhibit secretions of pituitary hormones, e.g.,, Somatostatin inhibits secretion of growth hormone., , Pituitary Gland :, , , Located in bony cavity called as sella tursica., , , , Attached to hypothalamus by a stalk., , , , Divided anatomically into : Adenohypophysis and Neurohypophysis., , , , , , Hormones released from hypothalamic neurons reach anterior pituitary, through portal system., Posterior pituitary is under neural control of hypothalamus., , 212, , Biology Class - 11
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1. Pituitary Gland, Pituitary Gland, Adenohypophysis (Anterior lobe), Neurohypophysis (Posterior lobe), (It stores hormones sureated by hypothalamus, , Pars distalis, Pars intermedia, Pars nervosa, Secretes, GH, , PRL, , MSH, TSH, , ACTH, , LH, , FSH, , Oxytocin Vasopressin, , Adenohypophysis :, Growth hormone (GH) : Oversecretion leads to gigantism and low secretion, causes dwarfism., Prolactin (PRL) : Growth of mammary gland and formation of milk in, them., Thyroid stimulating hormone (TSH) : Stimulates synthesis and secretion, of thyroid hormones from thyroid gland., Adrenocorticotrophic hormone (ACTH) : Stimulates synthesis and, secretion of steroid hormones called glucocorticoids from adrenal cortex., Luteinizing hormone (LH) : Synthesis and secretion of hormones called, androgens in males, and helps in ovulation and maintenance of corpus luteum, in females., Follicle stimulating hormone (FSH) : Regulate spermatogenesis in males,, and growth and development of ovarian follicles in females., Oxytocin helps in contraction of uterus during child birth and milk ejection, from mammary gland in females., Vasopressin : Acts on kidney and stimulates reabsorption of water and, electrolytes by distal tubules to reduce water loss through urine. It is also, called as Anti Diuretic Hormone (ADH)., Acrommegaly : It is a condition when the pituitary gland makes too much, growth hormone. It is due to a tumour in pituitary gland. Person suffering, from acromegaly (acro means tip and megaly means enlargement) may, gradually develop a long face with protruding lower law, enlarged nose and, wider spacing between teeth and enlarged hands and feet., 2. Pineal Gland :, Located on dorsal side of forebrain., , , Chemical Coordination and Integration, , 213
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, , 3., , , , , , , , , , , , , , , 4., , , , , , , 5., , , , , , , 6., , , , Secretes Melatonin to regulation 24-hours rhythm, sleep-wake cycle,, menstrual cycle, pigmentation etc., Thyroid Gland :, Has two lobes on either side of trachea interconnected by isthmus (connective, tissue)., Composed of follicles and stromal tissues., Follicular cells synthesis thyroxine (T4) and tri-iodothyronine (T3)., Iodine is necessary for normal functioning in of thyroid., Goitre (Hypothyroidism) : Enlargement of thyroid gland; Hypothyroidism, may lead to mental retardation and stunted growth (cretinism) Deaf-mutism, in the baby if it occurs during pregnancy., Hyperthyroidism : Occurs due to cancer or due to development of nodules, in thyroid glands. Effects body physiology as abnormal high levels of thyroid, hormones is synthesised. Basic metabolic rate increase., Exophthalmic goitre : It is a form of hyperthyroidism, characterised by, enlargement of thyroid gland, protrusion of eye balls and increased BMR, Thyroid hormone controls protein, carbohydrate metabolism., Also secretes a protein hormone called Thyrocalcitonin (TCT) which regulates, blood calcium level., Parathyroid Gland :, Present on back side of thyroid gland. Each lobe of thyroid gland has its one, pair., Secrete peptide hormone called parathyroid hormone (PTH) which increases, calcium levels in blood so called hypercalcemic hormone., PTH stimulates bone resorption, and reabsorption of calcium from blood and, reabsorption of calcium by renal tubules, thus increasing blood Ca++ level., Thymus Gland, Located on dorsal side of heart and aorta., Secrete peptide hormones called Thymosins which play role in differentiation, of T-lymphocytes (help in cell mediated immunity.), Thymosins also produce antibodies and provide humoral immunity., Immunity of old people usually becomes weak as thymus gets degenerated, with age., Adrenal Gland, Located at anterior part of each kidney., Has centrally located adrenal medulla and at periphery in adrenal cortex., , 214, , Biology Class - 11
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Adrenal medulla secretes adrenaline (epinephrine) and nor adrenaline, (norepinephrine), commonly called as catecholamines or emergency, hormones or hormones of fight or flight., These hormones increase heart beat, rate of respiration, breakdown of, glycogen thus increase blood glucose level, breakdown of lipids and protein,, alertness, raising of hairs, sweating etc., Adrenal Cortex-(3 layers) :, Zona reticularis (inner layer), , Zona fasciculata (middle layer), , Zona glomerulosa (outer layer), , , , , Adrenal cortex secretes :, , 1. Androgenic steroids :, , , Secreted in small amounts., , , , Play role in growth of axial pubic and facial hair during puberty., , 2. Glucocorticoids :, , , Involved in carbohydrate metabolism., , , , Stimulates gluconeogenesis, lipolysis and proteolysis., , , , e.g., Cortisol which is also involved in cardio-vascular and kidney functions., , , , It also suppresses immune response and stimulates RBC production., , 3. Mineralocorticoids :, , , , , , , , Regulate balance of water and electrolytes in body., e.g., Aldosterone which also helps in reabsorption of NA+ and water excretion, of K+ and phosphates ions from renal tubules., When adrenal cartex is damaged, it does not produce enough cortisols (which, regulate body’s reaction to stressful situations) and aldosterone., It result in Addison’s disease. Symptons of addison’s disease are weak, muscles, extreme fatigue, increased skin pigmentation, weight loss, sores, in mouth and depression., , Two major causes :, 1. Primary adrenal insufficiency where our immunity system mistakes adrenal, for an antigen and tries to damage it., Chemical Coordination and Integration, , 215
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2. Secondary adrenal insufficiency-when pituitary gland can’t produce ACTH, 7. Pancreas :, , , , , , , , , , Has both exocrine and endocrine function., Contains about 1-2 million islets of Langerhans which has glucagon secreting, α-cells and insulin secreting β-cell., Glucagon : Peptide hormone, stimulates glycogenolysis by acting on, liver cells. Also, stimulates gluconeogenesis. Hence called hyperglycemic, hormone., Insulin : Peptide hormone, acts on hepatocytes and adipocytes to enhance, cellular glucose uptake, stimulates conversion of glucose to glycogen, (glycogenesis), so decrease blood glucose level called hypoglycemic, hormone., Deficiency of insulin causes diabetes mellitus in which loss of glucose occurs, through urine. Excessive hunger and thirst (polydipsia) are other symptoms, of Diabetes., , , Glycogenolysis : Breaking of glycogen into glucose., , Gluconeogenesis : Formation of glucose from substances other than glycogen., , Glycogenesis : Conversion of glucose into glycogen., 8. Testis :, , , , , A pair of testis composed of seminiferous tubules and interstilial cells is, present in the scrotal sac of males., Leydig cells (interstitial cells) produce androgens (mainly testosterone) which, regulate development and maturation of male accessory sex organs, formation, of secondary sex characters and play stimulatory role in spermatogenesis., Male sexual behaviour (libido) is influenced by androgens., , Ovary : A pair of ovaries which produce one ovum in each menstrual cycle are, present in abdomen in females., , , , Ovary composed of ovarian follicles and stromal tissue., Estrogen synthesised by growing ovarian follicles helps in stimulation of, growth of female secondary sex organs, female behaviour, mammary gland, development and female secondary sex characters., , 216, , Biology Class - 11
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, , Ruptured follicle form corpus luteum which secretes progesterone., Progesterone supports pregnancy and stimulates alveoli formation and milk, secretion in mammory glands., , Hormones secreted by tissues which are not endocrine, glands :, (a) Heart : Atrial wall secrets Atrial Natriuretic factor (ANF) which decreases, blood pressure by dilation of the blood vessels., (b) Kidney : Juxtaglomerular cells secretes erythropoietin which stimulates, erythropoiesis (RBC formation)., (c) Gastro-intestinal tract : it secrets four peptide hormones., , , , , , Gastrin : Acts on gastric glands and stimulates secretion of hydrochloric, acid and pepsinogen., Secretin : Acts on pancreas and stimulates secretion of water and bicarbonation., Cholecystokinin (CCK) : Act on pancreas and gall bladder to stimulate, secretion of pancreatic juice and bile juice respectively., , Gastric inhibitory peptide (GIP) : Inhibits gastric secretion and motility., Mechanism of hormone action : By hormone receptors of two kinds, i.e.,, (a) Located on membrane of target cell, These are membrane bound receptors., From hormone receptor complex., ↓, Leads to biochemical changes in tissue., ↓, Release of second messengers like (cyclic AMP, IP3, Ca2+ etc.) which regulate, cellular metabolism., (b) Located inside the target cell, These are intra cellular receptors., Hormones (steroid hormones iodothyronines etc.) interact with them and, cause physiological and developmental effects of regulating gene expression., , Chemical Coordination and Integration, , 217
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Questions, Very Short Answer Questions, , (1 mark each), , 1. Which two system Coordinate and regulate physiological functions of our, body ?, 2. What is the role of melanocyte stimulating hormone ?, 3. Name the hormones which act antagonistically in order to regulate calcium, levels in the blood., 4. Give the names of any one glucocorticoid and one mineralocorticoid., 5. How does artrial natriuretic factor decreases blood pressure ?, 6. Which structure is formed from ruptured follicle in females ? What is its, role ?, 7. Immunity of old persons becomes very week. Give reason., , Short Answer Questions-I, , (2 marks each), , 8. What happens if a person suffers from prolonged hyperglycemia ?, 9. What are the two modes through which the hypothalamus causes the release, of hormones by pituitary gland ?, 10. Androgen regulated the development, maturation and other important, functions in human male. List them., 11. Mr. Akshay notices that his shoe size has progressively increased. He also, observes that shape of his face has gradually changing with protruding lower, jaw. What can be the cause for all changes. Name the disorder., , Short Answer Questions-II, , (3 marks each), , 12. Define hormone and classify them on basis of their chemical nature., 13. How do oxytocin, progesterone and estrogen differ from each other ?, 218, , Biology Class - 11
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14. What are the disorders caused and the effects produced due to malfunctioning/, improper secretion from thyroid gland ?, 15. Name the disease/disorder caused by :, (a), , Excessive secretion of Thyroid harmone in adults, , (b), , Insufficient amount of insulin secreted by pancreas, , (c), , Damage of adrenal cortex., , Long Answer Questions, , (5 mark each), , 16. ‘The master gland regulates a number of physiological functions in our body.’, Give reasons and explain., , Answers, Very Short Answers, , (1 mark each), , 1. Nerual system and endocrine system., 2. Acts on melanocytes and regulates pigmentation of skin., 3. Thyrocalcitonin (TCT) and parathyroid hormone (PTH)., 4. Glucocorticoid—Cortisol; Mineralocorticoid—aldosterone., 5. By dilation of the blood vessels., 6. Corpus luteum which secrets progesterone., 7. Thymus gland degenerates with age., , Short Answer Questions-I , , (2 marks each), , 8. Gets affected by diabetes mellitus which causes loss of glucose through urine, and formation of harmful ketone bodies., 9. Through hypothalamic neurons control anterior pituitary gland. Through, neural regulation controls posterior pituitary gland., , Chemical Coordination and Integration, , 219
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10. Refer Points to Remember., 11. Increased secretion of growth harmone Acromegaly, , Short Answers Questions-II , , (3 marks each), , 12. Refer Points to Remember and page no. 338, NCERT, Text Book of Biology, for class XI., 13. Oxytocin causes milk ejection and contraction of uterus at time of child birth., Progesterone–causes milk secretion and maintains pregnancy., Estrogen : Refer Points to Remember., 14. Refer Points to Remember., 15. (a), , Expotthalmic goitre, , (b), , Diabetes, , (c), , Addison’s disease, , Long Answers Questions-II, , (3 mark each), , 16. Explain the role of pituitary gland + Refer Points to Remember., , , 220, , Biology Class - 11
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Practice, , Practice Paper–I, , (Solved), Subject : Biology (044) (Theory), , Class : XII, , Session-2016-17, Time : 3 Hrs.], , [MM : 70, , General Instructions :, (i) All Questions are compulsory., (ii) The question paper is consist of A, B, C, D, E and F Sections. Section ‘A’, Contain 5 Questions of 1 mark each, Section ‘B’ is of 5 Questions of 2 marks, each, Section ‘C’ has 12 Questions of 3 marks each, Section ‘D’ contains 1, Question of 4 marks, Section ‘E’ contains 1 Question of 5 marks. Section, ‘F’ contains 2 Question of 5 marks each from the content of OTBA., (iii) There is no over all choice. However, an internal choice is given in 1 Question, of 2 marks, one question of 3 marks and one question of 5 marks. Students, have to attempt only one question from such alternative questions., (iv) Whenever necessary or asked the diagrams should be neat and clean and, well labelled., , Section A, 1., , How re Monographs different from Manuals?, , 2., , Name the enzyme which hydrolysis protein in acidic medium in audult, human., Paper, , 221
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3., , Name vegetative propagules present in Agave and water hyacinth., , 4., , Which two factors affect water potential?, , 5., , L and B islet of Langerhns Decretes two hormones to maintain the glucose, balance in blood. Name them., , Section B, 6., , In angiosperms, sieve tubes are associated with specialized cells of, parenchyma. Name these cells and briefly write how do they function., OR, Mention the importance of Trichomes and root hair for a plant., , 7., , Write two advantages of multicellulaity to an organism., , 8., , What do you understand by secondary structure of protein. Explain., , 9., , Briefly describe two pathways through which mineral nutrients absorbed, by roots are carried to the xylem., , 10., , Inspiratory muscles and expiratory muscles play very important role in, respiratory process. Explain their role., , Section C, 11., , Define Metamerism? Differentiate between metameric and non metameric, segmentation., , 12., , Where do you find Adipose tissues in human body? Describe its structure, only through diagram. Give its important function., , 13., , Draw a neatly labelled diagram of T.S. Dicot stem. (any six correct, Labellings)., , 14 . Expand the term ‘RuBisCO’. How does it act as carboxylase and oxygenase, respectively?, 222, , Biology Class - 11
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15., , Explain the mechanism of carbon dioxide transport from tissues to the lungs, by Red Blood cells., , 16., , Discuss the role of middle ear in hearing., , 17., , Explain the process of ATP formation during aerobic respiration (In, mitochordria) with the help of diagram., , 18., , Some symbiotic organisms are very good pollution indicators and composed, of a chlorophyllous and a non-chlorophyllous members. Name and Describe, them., Or, The leaves in gymnosperms are adopted to withstand xerophytic conditions., Justify., , 19., , Maize grain is usually called as fruit and not a seed. Why?, , 20., , List out six major proteins and their functions., , 21., , Write two functions of each of the following Golgi Complex, Endoplasmic reticulum, plastids., , 22., , What is stroke volume? How is it related to cardiac output?, , Section D, 23., , Sumit watched a T.V. programme with showed that fruiters use chemicals in, their godown to induce artificial ripening green and unripe fruits purchased, from farmers. He was surprised to see that green and unripe fruits are, transported to destined places. He asked his biology teachers the reason, for it., (i), , Which compound is used to induce artificial ripening of fruits?, , (ii), , Why only green and unripe fruits are transported by farmers?, , (iii) Mention only two values reflected by fruiter., , Paper, , 223
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Section E, 24. What is cell cycle? Explain the events occurring during the cell cycle of a, somatic cell., Or, (a), , Write a note on significance of meiosis., , (b), , Differentiate between anaphase I of meiosis and Anaphase of mitosis., , (c), , , What do you understand by Synapsis? In which stage of Prophase-I, you observe it., , 25., , Explain the counter current mechanism in Vasa Reeta. Also mention its, significance., Or, , Explain the important steps of sliding filament theory of muscle, contraction., 26., , 224, , What is Glycolysis? Explain different steps of Glycolysis. What are products, of light reaction? Name first stable product of C3 plants. Explain different, steps of Calvin cycle., , Biology Class - 11
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ANSWER OF PRACTICE TEST PAPER–I, Subject : Biology (044) (Theory), (Solved), Class : XI, (Session-2017-18), , Time : 3 Hrs., , MM : 70, , Section A, 1., , Monographs contain information on any one taxon and Manuals provide, information for identification of name of species in an area., , 2., , Pepsin., , 3., , Agave - Bulbic, , 4., , Concentration of solute, external pressure., , 5., , α - cell : Glucgon, β - cell : Injulin., , Section B, 6., , Companion Cells., Sieve tubes lacks nuclei. Their functions are controlled by the nucleus of, companion cells. They help in the translocation of the food material., Or, Trichomes are multicellular epidermal hairs on the stem, seeds and fruits., They help in protection dispersal of seeds and fruits and reduction of water, loss., Root hair helps in absorbing water and mineral from soil., , 7., , Multicellularity results in producing division of Labour amongst its cells, and enhance the chances of survival., , Paper, , 225
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8., , Polypeptide chain undergoes folding or coiling which is stabilized by, hydrogen bonding. Right handed helices are observed eg. fibrous protein, in hair, nails., , 9., , A protoplast pathway- The ions enter the cell wall of Epidermis and move, across the cell wall from epidermis to xylem and finally accumulated, their Symplast pathway - The ions enter the cytoplasm of Epidermis and, move across the cytoplasm of epidermis to cytoplasm of pericycle through, plasmodesmata and finally to xylem vessels., , 10., , The contraction of the external inter costal muscles and diagphragm →, Increase in volume of thoracic cavity → Inspiration., Relaxation of the inspiratory muscles – Decrease the volume of thoracic, cavity – Expiration., , Section C, 11., , Metamerisation – Segmentation of External and internal body into linear, sequence of segments (repetition of atleast some organ)., Metameric Segmentation : External segmentation correspond to internal, segmentation eg. Earthworm., Non-metameric Segmentation : External segmentation do not correspond, internal segmentation eg. Platyhelminthes., , 12., , Adipose tissues are located beneath skin. Fals are stored in them. For, Diagram refer to NCERT page no.103 figure 7.4 (b)., , 13., , Refer to diagram at NCERT Page No. 92 figure 6.7 (a)., , 14., , RuBisCO– Ribulose bisphosphate carboxylase-oxygenase., RuBisCo brings about carboxylation during Calvin cycle in photosynthesis, under high concentration of Oxygen and Increase in temperature, RuBisCO, act as oxygenase and carry out photorespiration., , 226, , Biology Class - 11
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15., , Transport of CO2 in the blood., CO2 + H2O, , H2CO3, Carbonic Acid, , HCO3- + H+., , About 20% of CO2 is transported by combining with free amino group of, Haemoglobin in RBC., 70% of CO2 is transported as bicarbonates of sodium (NaHCO3) and, potassium (KHCO3)., 16., , 17., , Middle ear, (a), , Tympanic membrane – act as resonator that produces vibration, of sound., , (b), , Ear Ossicles – Transmit sound waves to internal ear., , (c), , Eustachian tube – help in equalising the pressure of either side of ear, drum., , Refer to diagram 14.5 on NCERT Page No. 234., The Synthesis of ATP from ADP and inorganic Phosphate using energy, from proton gradient is called oxidative phosphorylation. This takes, place in elementary particles present on the inner membrane of crystal of, mitochondria. This process in mitochondria is catalysed by ATP synthetase., This complex has two major components F0 and F1. F0 acts as channel for, proton and F1 acts as on ATP synthetase., , 18., , Lichens are symbistic association between algal components (phycobiont), and fungal components (mycobiont). Algae provides food. Eungi provides, shelter and absorb nutrients and water for alga. They are good pollution, indicator as they do not grow in polluted area., , 19., , Maize grain is a single seeded fruit in which the seed covering on testa is, fused with pericarp or fruit wall. A micropyle is not found but base of style, is present., , Paper, , 227
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20., , Collagen – Intercellular group substance, Trypsin – Enzyme, Insulin-Hormone, Antibody – Fights infectious agents, Receptor – Sensory perception, GLUT-4 – Enable glucose transport., , 21., , Golgi Complex :, (i), , Perform packaging of Material, , (i), , Site for formation of glycoprotein and glycolipids., , (iii), , Endoplasmic reticulum – Synthesis of protein and lipids., , Plastid : Storage of protein, site of photosynthesis., 22., , During are cardiac cycle or one heart beat the volume of blood pumped by, the heart is called stroke volume. This is normally 70 ml., The amount of blood pumped by heart per minute is called cardiac out put., This is 5 L approximately., , Section D, 23., , (a), , Ethophen release Ethylene which causes ripening of fruits., , (b), , Mature fruit will get spoiled during Transportation., , (c), , Scientific knowledge and scientific temper., , Section E, 24., , Cell cycle – Sequence of events by which a cell duplicate its genome,, synthesis the other constituents of the cell and eventually divides into two, daughter cell., Phases – refer to diagram 10.1 pg. NCERT 163., Phases of cell cycle –, , , 228, , Interphase, – M-Phase (Mitosis), , Biology Class - 11
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(A), , Interphase :, , G1 – Cell metabolically active and g row continuously but does not, replicate DNA., , , S Phase – DNA replication occur., , G2 Phase – Proteins are synthesized in preparation for mitosis while, cell growth continues., (B), , M-Phase (Mitosis) - stats with nuclear division (kalgokinesis) and, then cytokinesis., Or, , (a), , Formation of genetic, Genetic variabling, maintaince of chromosomal, number., , (b) Anaphase of mitosis : Centromeres spl and chromatids seperate;, chromatials moves to opposite poles due to shortening of Spindle fibres., Anaphase I of meiosis : Homologous chromosanus seperate while chromatids, remain associated at their centromeres., (c) Pairing of homologus chromosomls. Synopsis is observed during, zygetene stage., 25., , The mechanism of concentration of the filtrate is said to be counter current, because outflow (in ascending limb) runs parallel to and in opposite direction, of inflow (in descending limb)., , •, , NaCl is transported by the ascending limb of (Henles loop) which is exchanged, with descending limb of Vasa-recta., , •, , NaCl is returned to the interstitium by ascending portion by vasa recta., , •, , Osmalality increase from 300 mosmol/2 in context to about 1200 mosoml/L, in inner medulla., , •, , Small amount of urea enter, the thin segment of ascending limb of Henle’s, loop which is transported back to interstitium by the collecting tubule., , Paper, , 229
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This mechanism helps to maintain a concentration gradient in the medullary, tubule interstitium., Refer 1. diagram 19.6 on NCERT Pg. 296., Or, •, , Central Nervous system initiate muscle contraction via motor Neuron., , •, , Motor Neuron – stimulate Muscle fibre → secrete neurotransmitter → generate, action potential in sarcolemma → Release of Ca2+ in sarcoplasm → Ca2+ binds, with troponin → Unmask active site → Myosin head binds to actin at active, site and form cross bridge using ATP. → Pulls the actin filament towards the, centre of ‘A’ band → Z lines also pulled thereby shortening of sarcomere i.e., contraction. I band get reduced, where the ‘A’ band retain the length., , During relaxation :, Cross bridge between Actin and myosin break → Ca2+ pumped back into, Sarcoplasmic cisternae → Actin filament slide out of ‘A’ band and length, of I band increase., 26., , Glycolysis : Breakdown of one molcule of glucose into 2 molecules of, pyurvuvic acid., Glycolysis take place in Cyloplasm., For schematic presentation refer to NCERT Pg. 229 Fig. 14.1., Or, ATP and NADPH, the product of light reaction are used in synthesis of food., The first CO2 fixation product in C3 Plants is 3-phosphoglyceric acid. The, CO2 acceptor is RuBP. Cyclic pathway is called Calvin cycle., It has three stages., , (i), , Carboxylation : CO2 + RuBP → 2 molecule of PGA., , (ii), , Reduction : Carbohydrate i formed at the expense of ATP and NADPH. It, involves 2 ATP for phosphorylation and 2 NADPH2 for reduction per CO2, molecule fixed., , 230, , Biology Class - 11
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(iii) Regeneration : RuBP is formed again., 6 turns of Calvin cycle and 18 ATP molecules are required to synthesize, one molecule of glucose (Fig. 13.8)., 6 CO2 + 6 RuBP + 18 ATP + 12 NADPH –––– C6H12O6 + 6 RuBP + 18ADP, + 18 pi + 12 NADP., , Practice Paper - II, , Subject : Biology (Theory), Class : XI, Time : 3 Hrs.], , [MM : 70, , General Instructions :, (i), , All Questions are compulsory., , (ii) Marks of each question are indicated against in., (iii) Wherever necessary, the diagram draw should be neat and wall labelled., , Section A, , , 1 Mark each, , 1., , Why are brown algae brown?, , 2., , Write the names of four classes of fungi., , 3., , What type of modification of root is found in, (a) Banyan tree, , (b) Mangrove trees., , 4., , Where is electrom transport system operative in mitochondria?, , 5., , Name the two accessory digestive organs in human beings., , Paper, , 231
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Section B, 2 Marks each, 6., , Write two differences between cartilogenons and bony fishes., Or, Enumerate the peculiar features that you find is phylum chordata., , 7., , What is Phyllotaxy? Give one difference between racemase and cymose, inflorescence., , 8., , Explain the fluid mosaic model of plasma membrane given by Singer and, Nicolson., , 9., , Name the stage of the cell cycle at which following events occur - (a) Pairing, of homologous chromosome (b) Replication of DNA (c) Separation of, humologens chromosemes (d) Dissolution of synaptonemal complex., , 10. Mention the location and function of malphigian tubales and gizzard in, cockroach., , Section A, 3 Marks each, 11. Differentiate between homosporus and heterosporons pteridophytes with, one example of each., 12. Write three differences between monocot and dicot stems., 13. Draw labelled diagram of Alimentary canal of cockroach and label following, post in it salivary gland, Crop, Gizzard, Hepatic caeca and colon., 14. (a), (b), , What are Polysomer? What is their function?, State the function of inclusion bodies in prokaryotes., Or, , Explain different types of chromosoms based on the position of centromere., 15. Compare glycosidic bond, peptide bond and ester bond., 232, , Biology Class - 11
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16. (b), , Why xylem and phloem are considered as complex permanent tissues., , (b), , Roots of dicot show exarch condition of Xylum. What does it mean?, , (c), , Name two types of mesophyll cells present in a Dicot leaf., , 17. Explain the initiation of muscle contraction. What is the role of sacroplosmic, reticulum, myosin head and F-actin filament during contraction in striated, muscle., 18. Explain he role of Pancrease and liver in the process of digestion of food., 19. What is meant by Apoplastic and symplastic pathways? Which of them does, not occur in endodermis and why?, 20. Which one of the plant growth regulators would you use, if you are asked, to –, (a), , Increase the length of a dwarf plant, , (b), , Delay in leaf senescence., , (c), , Inducing rooting in a twing, , 21. On what factors do binding of oxygen with heamoglobin primarily depend?, What do you understand by Oxygen dissociation curve?, 22. Name three hormones secreted from, anterior pitutary and their functions., , Section D, 4 Marks each, 23. One day Rahul visited his friend Gaurang along with his father. Suddenly,, his father start fealing uncomfortable and congestion in lungs. Gaurang, immediately rushed him to a nearby hospital. Doctor praised Gaurang for his, timely decision otherwise Rahul’s Father could have died of heart failure., (i), , What is the difference between heart failure and cardiac assest?, , (ii), , What values do you observe in Gaurang?, , Paper, , 233
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Section E, 24. Explain the process of Generation and condution of a nerve impulse., Or, Explain the different mechanism to regulate kidney functions is human, beings., 25. Explain different steps of a Kreb’s cycle. Why i it called TCA cycle?, Or, Explain different steps of cyclic photo-phosphorylation. How is it different, from non-cyclic photo phosphorylation., 26. (a), , What is Imbibition ? What are conditions essential for imbibition., , (b), Explain different steps of nodule formation is roots of leguminons, plants., Or, Expain different steps of Calvin cycle. Why is it called C3 cycle?, , 234, , Biology Class - 11
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Practice Paper - III, , Subject : Biology (Theory), Class : XI, Time : 3 Hrs.], , [MM : 70, , General Instructions :, (i), , All Questions are compulsory., , (ii) The question paper is consist of five section A, B, C, D & E., (iii) Section A contains 5 questions each of 1 marks, Section-B contains 5 questions, each of 2 marks, Section-C contains 12 questions each of 3 marks, Section-D, contains 1 question of 4 marks and Section-E contains 3 questions each of, 5 marks., (iv) There is not over all choice. Howeer an internal choice has been provided, in oe question of two marks. 1 question of 3 mark and in all 3 questions of, 5 marks., , Section A, 1., , In Biological classfication of Animals write the name of ‘family’ and ‘order’, to which man belong., , 2., , When stamens are called epiphyllous., , 3., , Name the cells that surround vascular bcendles in dicot leaf., , 4., , Name the monomers which are linked by (a) peptide bond, (b) glycosidic, bond to make their polymers., What is the shape of gaurd cell in (a) Moncot leaf and (b) dicot leaf., , Section B, 6., , Name the class of algae to which Laminaria belong. Draw labelled diagram, of Laminaria showing its holdfast, stipe and frond., , Paper, , 235
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7., , Name the class of fungi to which Mucor and Rhizopus belong. Write 3 special, features of this class in terms of habitat mode of nutrition and mycelium., , 8., , Write three important features of cartilagenous fish and bony fish. Also give, one examples of each of these., , 9., , Draw labelled diagram of alimentary canal of cockroach and write the role, haepetic coeca and malpighian tubales in it., , 10. Write structure, function and location of compouned epithelium in Animals., Or, Write structure of Parenchyma in plant. Write the location and function of, this tissue., , Section C, 11. Write six special features of flowers having floral formulaBr + + P(3) + (3) A3+3 G(3)., 12. Write 3 main anatomical difference in Monocot and Dicot stem., 13. What are chromosomes & where these exist in cell. Classify the chromosomes, based on the position of centromere. Also show these chromosomes by, diagrams., 14. What are three different factors which affect enzyme activity. Explain and, show their effect by labelled diagram., 15. Along with labelled diagram explain special features of metaphase of mitosis., 16. What do you mean by Isotonic, hypotonic and hypertonic solution with, respect to cytoplasm of a cell? What will happen to a cell when it is placed, in (a) isotonic solution (b) hypotonic solution (c) hypertonic solution?, 17. Write and explain 3 physical properties of water that help in rise of water, from root to top of plants. Write the effect/role of these properties in water., 18. What are three different criteria for essentiality of nutrients for plants. Explain, each., , 236, , Biology Class - 11
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19. Name two plant hormones which are said to be antagonistic in their function., Write role of these plant hormones., 20. What are three main digestive glands asociated with human alimentary canal?, Show these by labelled diagram. Write one important role of each gland., 21. How are respiratory gases O2 & CO2 transported by blood between lungs, and tissues of body? Explian., 22. What is Lymph? How is is formed? Write two main differences between, blood plasma and lymph., Or, What are components of Malpighran body in a nephron? Show these by, labelled diagram and write its role., , Section D, 23. Amit met an accident while crossing the road with his friend Asif and Joseph., He was hospitalized and his parents were informed. After testing the Amit’s, blood groups Doctor asked Amit’s parents to arrangement blood of AB-ve, groups. Asif offered himself to donate blood to Amit. But Amit’s parents, hesitated. Joseph made agree to Amit’s parents and Asif donated blood to, Amit to save his life., Answer these : 1. Why did Amit’s parents hesited to take blood from Asif., 2., , How did Joseph made agree to Amit’s parent., , 3., , Write two life skills of Joseph., , Section E, 24. What do you mean by light reaction and dark reaction that occur during a, photosynthesis? Where the reactions happen in chloroplast? Explain the role, of these reactions in photosynthesis., Or, Define Glycolysis. Is this initial and essential process for aerobic, an aerobic, respiration and fermentation. Explain the steps of glycolysis only by flow, diagram., Paper, , 237
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25. Draw a labelled diagram of cell cycle showing its different phaes. And explain, G1, S and S2 paase of cell cycle., Or, Answer the following questions :, (a), , What are components of a polynucleotide., , (b), Lipids have molecular weight less than 800 Dalton yet these are put, in category of macromolecules. Why?, (c), , Write name and structural formula of an amino acid and nueleotide., , (d), , Write names of two autonomous body of a cell and their function., , 26. Draw a labelled diagram of internal structure of human eye and write role, of each part (minimum 8 points)., Or, What do you mean by endocrine glands? Write location and function of each, endocrine gland in humans., , 238, , Biology Class - 11
