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KVS RO RAIPUR, REVISION MATERIAL ON, SUBJECT: BIOLOGY, (PART I- STUDY MATERIAL - PAGE 2- 69, PART 2 -SAMPLE PAPER – PAGE 71-121 ), PREPARED BY PGT BIOLOGY, SMT E. KUMAR, KV NO 4 KORBA, SMT GEETU, KV CISF BHILAI, SMT RANJANA, KV BAIKUNTHPUR, SMT P PARASAR, KV NO 3 SECL KUSHMUNDA, SH MANISH TIWARI, KV NO 2 NTPC KORBA, SH.A K ROY, PGT BIOLOGY KV DONGARGARH, DR. A MATHEW, KV DHAMTARI, COORDINATED BY, HARILAL PADHAN, PRINCIPAL KV RAIGARH, GUIDED BY, SH A.K MISHRA, ASSISTANT COMMISSIONER KVS RO RAIPUR, CHAPTER-2: Sexual reproduction in flowering plants, A.ONE MARK QUESTIONS (VSA-I), Name the parts of the flower which the tassels of corn cob represent., Ans- stigma and style, A bilobed, dithecous anther has 60 microspore mother cells per microsporangium. How many male gametophytes this anther can produce?, Ans – 60 * 4 = 240 male gametophytes, Name the part of the of gynoecium that determines the compatible nature of pollen grain., Ans- stigma, 4. Why are pollen grains produced in enormous quantity in maize?, Ans- to compensate for the uncertainties of pollen grains to come in contact with stigmas and associated loss of pollen grains., 5. Name the type of pollination in self – incompatible plant., Ans- cross pollination., 6. What is the ploidy of PEN?, Ans – 3n, 7. How many eggs are present in an embryo sac?, Ans – 1, 8. Even though each pollen grain has two male gametes, why are atleast 10 pollen grains and not 5 pollen grains required to fertilize 10 ovules present in a particular carpel?, Ans- because one of the 2 male gametes fertilizes the egg other is used to form PEN .so 10 pollen grains are required to fertilize the 10 ovules., 9. What are parthenocarpic fruits?, Correct definition., 10. What is scutellum?, Ans- shield shape monocotyledon., 11. What is a pollen bank?, Ans- pollen stored or preserved in liquid nitrogen for years., 12.An anther with malfunctioning tapetum often fails to produce viable male gametophytes.Give one reason., Ans- the male gametophytes die out due to mal nutrition., 13. In case of polyembryony, if an embryo develops from the synergid and another from the nucellus which is haploid and which is diploid?, Ans-synergid embryo – haploid, nucellus embryo – diploid, 14. Give an example of a plant which came into India as a contaminant and is a cause of pollen allergy., Ans- Parthenium, 15 How many meiotic divisions are required to produce 88 seeds in a guava fruit?, Ans- Seeds = egg + pollen -----88 +88/4 =110 meiotic divisions., B. ASSRETION AND REASONING QUESTIONS:, In the following questions a statement of assertion followed by a statement of reason is given .Choose the correct answer out of the following choices., (a) Assertion and reason both are correct statements and reason is correct explanation for assertion., (b) Assertion and reason both are correct statements but reason is not correct explanation for assertion, (c)Assertion is correct statement but reason is wrong statement., (d) Assertion is wrong statement but reason is correct statement., 1.Assertion :The endosperm of angiosperms is generally triploid (3n)., Reason : It develops from primary endosperm nucleus formed by fusion of haploid gamete and diploid secondary nucleus., 2. Assertion : Dictogamy refers to maturation of male and female sex organs at different times., Reason :This is a safeguard against cross fertilisation., 3. Assertion : Megaspore mother cell undergoes meiosis to produce four megaspores., Reason : Megaspore mother cell and megaspores are both haploid., 4. Assertion: Entomophilous plants produce less pollen when compared to anemophilous plants., Reason : The wastage of pollen is reduced to the minimum in entomophilous, because of the directional pollination., 5. Assertion : A structure of a typical microsporangium in angiosperms consists of four wall layers-epidermis, endothecium, middle layers and tapetum., Reason : The function of outer three wall layers is protection and also help in dehiscence of anther to release pollen., 6. Assertion :Apollen grains can withstand harsh conditions., Reason : The exine of pollen grains is made up of sporopollenin which is resistant to high temperatures, strong acids or alkali as well as enzymatic degradation., 7. Assertion : In plants, apomixis is a type of asexual reproduction that mimics sex reproduction., Reason : In apomixis seeds are produced without the fusion of gametes., 8. Assertion : In coconut, the water represents the free nuclear endosperm and tne white kernel represents the cellular endosperm., Reason : PEN undergoes a number of free nuclear divisions which are followed by wall formation., 9. Assertion : In monosporic type of embryo development megaspore is situated towards the micropylar end and remains functional., Reason :In monosporic development the embryo sac develops from a single functional megaspore., 10. Assertion : Microspore is the first cell of male gametophyte., Reason : It is diploid in nature., ANSWERS:, 1.(a) 2.(c) 3.(c) 4.(b) 5.(b) 6.(a) 7.(a) 8.(c) 9.(d) 10.(c), C. 2 MARKS QUESTIONS: (VSA TYPE 2), Banana is a parthenocarpic fruit whereas oranges show polyembryony. How are they different from each other with respect to seeds?, Ans. Banana fruits are seedless, develop from ovary without fertilization hence parthenocarpic. An orange contain seeds with more than one embryo thus it shows polyembryony, Geitonogamous flowering plants are genetically autogamous but functionally cross pollinated. Justify, Ans. Geitonogamous flowering plants are genetically autogamous as gametes come from the same parent plant but since the pollen grains are being transferred to a different. flower which needs a pollinating agent, it is functionally an example of cross pollination., 3. In the given figure of a dicot embryo, label the parts (A) and (B) and give their function., Ans. A = Plumule, To form shoot system, B = Cotyledons , Storage of food [ ½ x 4], 4.Why are cleistogamous flowers invariably autogamous?, Ans. In a cleistogamous flower, the flower never opens and when the anther dehisce, the pollen grains fall on the stigma of the same flower and thus it is strictly autogamous, 5. Identify the types of flower shown in A and B. Which out of the two will produce an assured seed, Ans. A – Chasmogamous flower, B – Cleistogamous flower [½+ ½] Cleistogamous flower produces assured seed set as they do not depend upon external agency for pollination [1], 6., ANS- A-MICROPYLE, B- OUTER INTEGUMENT, C- INNER INTEGUMENT, D- EMBRYO SAC, 7. Among the animals, insects particularly bees are the dominant pollinating agents. List any four characteristic features of the insect pollinated flower, Ans.1. Flowers are large 2. Colourful petals of flowers 3. Presence of fragrance 4. Rich in nectar, 8. Name the product of fertilization that forms the kernel of coconut. How does the kernel differ from coconut water? Ans. Endosperm forms the kernel of coconut. Coconut water is free nuclear endosperm whereas kernel is cellular endosperm., 9. Some angiosperm seeds are said to be ‘albuminous’, whereas few others are said to have a perisperm, Explain each with the help of an example., Ans. Some angiospermic seeds are albuminous as they retain endosperm even after embryo development, i.e. not completely consumed by embryo, e.g. wheat, maize, castor. While in some angiospermic seeds remnants of nucellus are persistent which is referred to as perisperm, e.g. black pepper and beet., 10. A) Mention the similarity between autogamy and geitonogamy?, B) How does geitonogamy differ from xenogamy?, Ans- A- both are genetically similar., B – In geitonogamy pollens are transferred from the anther to the stigma of the same flower but in xenogamy the pollen grain is transferred from the anther to the stigma of the flower of different plant., D. 3 MARKS QUESTIONS (VSA TYPE 3), Continued self- pollination lead to inbreeding depression. List three devices, which flowering plant have developed to discourage self-pollination?, Ans. (a) Release of pollen and stigma receptivity is not synchronized in some species (b) Anther and stigma is at different position/heights in some plants, (c) Self-incompatibility a genetic mechanism., 2. Draw the diagram of microsporangium of an angiosperm and label any four parts. State the function of its innermost wall layer?, ANS- ref to fig. no – 2.3 (b) ncert book. Tapetum nourishes the developing pollen grains [2+1], 3. Given below are the events that are observed in artificial hybridisation programme. Arrange them in the correct sequence order in which they are followed in the hybridisation programme., a) re-bagging, b) Selection of parents, c) bagging, d) dusting the pollen on stigma, e) emasculation, f) collection of pollen from male parent, Ans. b) Selection of parent e) emasculation c) bagging f) collection of pollen from male parent d) dusting the pollen on stigma a) re-bagging, Fertilization is essential for production of seed, but in some angiosperms, seeds develop without fertilization i) Give an example of an angiosperm that produces seeds without fertilization. Name the process, ii) Explain the two ways by which seeds develop without fertilization, Ans. i) in the members of family Asteraceae, seeds develop without fertilization. This process is apomixes, ii) Two ways by which seed develop without fertilization a) in some species, diploid egg (2n) egg cell is formed without reduction division and develops into embryo without fertilization, 5. Where are the following structures present in a male gametophyte of an angiosperm? Mention the function of each one of them, a) Germ pore, b) Sporopollenin, c) Generative cell, Ans a. Germ pores: exine of pollen grain. It is the site from where pollen tube emerges, b. Sporopollenin: Exine of pollen grain. It protects the pollen grain from high temperature, strong acids, enzymes and alkali, c. Generative cell: present in pollen grain. These give rise to two male gametes, E.CASE STUDY QUESTIONS (4-MARKS EACH), Read the following and answer any four questions from (i) to (v) given below:, 1) POLLINATION, Pollination, transfer of pollen grains from the stamens, the flower parts that produce them, to the ovule-bearing organs or to the ovules (seed precursors) themselves. Self-pollination occurs in flowers where the stamen and carpel mature at the same time, and are positioned so that the pollen can land on the flower’s stigma. This method of pollination does not require an investment from the plant to provide nectar and pollen as food for pollinators. Flowers often attract pollinators with food rewards, in the form of nectar. Pollinators are a key part of healthy ecosystems. A wider diversity of pollinators in many ecosystems is related to greater overall biodiversity, or variety among living organisms. These living organisms include our cultivated plants, which depend on pollinators. As native pollinators lose more and more habitat, they need our support if we want to continue to benefit from the vital pollination services they provide., i) If a pollen of a flower falls on the stigma of another flower belonging to same plant it is, a) Genetically self-pollination and ecologically cross pollination, b) Ecologically cross pollination, c) Genetically and ecologically cross pollination, d) None of these, Ans. a), ii) Attractants and rewards are required for, a) Hydrophily, b) Anemophily, c) Entomophily, d) Cleistogamy, Ans. c), iii) Assured seed set is possible even in absence of pollination in flowers which are, a) Chasmogamous, b) Cleistogamous, c) Xenogamous, d) Geitonogamous, Ans. b), iv) Pollination in water hyacinth and water lily is brought about by the agency of, a) Bats, b) Water, c) Molluscs, d) Insects or Wind, Ans. d), v) Plants with ovaries having only one or a few ovules are generally pollinated by, (a) bees, (b) butterflies, (c) birds, (d) wind, Ans. (d) wind, 2) Read the following and answer any four questions from (i) to (v) given below:, The Megasporangium (Ovule):, Let us familiarize ourselves with the structure of a typical angiosperm ovule. The ovule is a small structure attached to the placenta by means of a stalk called funicle. The body of the ovule fuses with funicle in the region called hilum. Thus, hilum represents the junction between ovule and funicle. Each ovule has one or two protective envelopes called integuments. Integuments encircle the nucellus except at the tip where a small opening called the micropyle is organised. Opposite the micropylar end, is the chalaza, representing the basal part of the ovule? Enclosed within the integuments is a mass of cells called the nucellus. Cells of the nucellus have abundant reserve food materials. Located in the nucellus is the embryo sac or female gametophyte. An ovule generally has a single embryo sac formed from a megaspore., i) Name the stalk of ovule structure attached to the placenta, a) Hilum, b) Nucellus, c) Micropyle, d) Funicle, Ans-d, ii). Name the junction between ovule and funicle, a) Hilum, b) Nucellus, c) Micropyle, d) Funicle, Ans-a, iii). What is the function of nucellus?, a) Abundant reserve food materials, b) Parasitic, c) No function, d) Both a and b, Ans. a), iv). Each ovule has---------- protective envelopes called integuments., a) one or two, b) two or three, c) none, d) both, Ans. a), v). Name the basal part of the ovule opposite the micropylar end ., a) chalaza, b) Nucellus, c) Micropyle, d) Funicle, Ans. a) Chalaza, F . 5 MARKS QUESTIONS ( LA), 1. Give reasons why:, i) Most zygotes in angiosperms divide only after certain amount of endosperm is formed., (ii) Groundnut seeds are exalbuminous and castor seeds are albuminous., iii) Micropyle remains as a small pore in the seed coat of a seed., (iv) Integuments of an ovule harden and the water content is highly reduced, as the see, Matures., (v) Apple and cashew are not called true fruits., Ans:, (i) To obtain nutrition from the endosperm for the developing embryo, zygotes, divide after formation., (ii) The groundnut seeds are exalbuminous because the endosperm is completely consumed during embryo development. Whereas, castor seeds are albuminous because the endosperm persists and is used up during seed germination., (iii) Micropyle remains as a small pore in the seed coat of a seed for the entry of water and oxygen required for germination., (iv) To protect the embryo and keep the seed viable, until favorable conditions return for germination., (v) In apple and cashew, apart from ovary, thalamus also contributes to fruit formation so they are not true fruits., 2. (A) as a senior biology student you have been asked to demonstrate to the students of, Secondary level in your school, the procedure(s) that shall ensure cross-pollination in a, Hermaphrodite flower. List the different steps that you would suggest and provide reasons for each one of them., (b) Draw a diagram of a section of a megasporangium of an angiosperm and label funiculus, micropyle, embryo sac and nucellus., Ans:, (a) The following steps would be followed:, i) Emasculation or removal of anthers from the flower bud, before the anther dehisce, to, avoid self-pollination., (ii) Bagging, to prevent contamination of its stigma with unwanted pollen grains., (iii) Rebagging, the stigma of the mature ovary are dusted with desired pollen grains and rebagged to allow the fruit to develop., b) For diagram refer to Fig. 2.7.(ncert book), 3. (a) Draw a labelled diagram of a mature embryo sac., (b) Why does a pollen grain possess two male gametes? Explain., Ans:, (a) Refer to Fig. 2.8(c) (Mature embryo sac). (Ncert book), b) Pollen grains possess two male gametes as it is required for double fertilization. Out of two male gametes, one male gamete moves towards egg cell and fuses with its nucleus to form a diploid cell called zygote and another male gamete fuses with two polar nuclei (secondary nuclei if they are already fused) to produce a triploid primary endosperm nucleus (PEN)., CHAPTER 3 HUMAN REPRODUCTION, ASSERTION – REASON TYPE QUESTIONS:-, Read the following Assertion –Reason based questions and gives the answers on the basis of following options:-, Assertion and Reason, both are correct and reason is the correct explanation of the assertion., Assertion and reason, both are correct but the reason is not correct explanation of the assertion., Assertion is correct and reason is incorrect., Assertion is incorrect and reason is correct., Assertion: - The ovulation takes place at the 14th day of the monthly ovarian cycle., Reason: - On 14th day the LH released in maximum quantity from anterior Pituitary Gland of a female., Ans. Assertion and Reason, both are correct and reason is the correct explanation of the assertion., Assertion: - In the ejaculation of the semen at once about 200-300 million sperms are present., Reason: - all sperms need to reach up to fallopian tube by crossing a number of barriers and during their journey; a number of sperms are used to die., Ans. Assertion and Reason, both are correct and reason is the correct explanation of the assertion., Assertion: - All the copulations not lead to pregnancy., Reason: - the ovum and the sperms not enter in the fallopian tube in synchronized way or in same time., Ans. Assertion and Reason, both are correct and reason is the correct explanation of the assertion., Assertion: - The head of the sperm is made by the acrosome, which is a giant lysosome., Reason: - Acrosome responsible to digest or dissolve all the barriers, in the pathway of sperm., Ans. Assertion and Reason, both are correct and reason is the correct explanation of the assertion., Assertion: - menstruation occurs from day 1 to day 5, in every ovarian cycle., Reason: - Less or no progesterone is responsible to sloughing off of all the tissue, during menstruation., Ans. Assertion and Reason, both are correct and reason is the correct explanation of the assertion., Following questions are MCQ type questions, select only 1 correct answer from the following options:-, In male reproductive system , to which cells , the Luteinizing Hormone give signals :-, Leydig’s Cells b. Setoli’s cell c. Primary spermatocyte d. spermatids, Ans. Leydig’s cells, In which organ does the spermatogenesis takes place :-, Testis b. Vasa efferentia c. Seminiferous tubules d. Vas deferens, Ans. Seminiferous tubules, At which part of fallopian tube the fertilization takes place :-, Ampulla b. Infundibulum c. Isthmus d. at any part it may occur, Ans. Ampulla, Which hormone is not secreted by the placenta :-, Oxytocin b. HPL c. HCG d. Relaxin, Ans. Oxytocin, Which of the following statement is incorrect :-, With respect to the ovary , only one ovary found active in a month., Ovulation takes place at the graafian follicular stage., After ovulation , the remaining granulose cells become cells secretary and called corpus luteum, A mature ovum is produced inside of the ovary., Ans. A mature ovum is produced inside of the ovary., GIVE THE ANSWERS OF FOLLOWING QUESTIONS IN 1 WORD OR 1 SENTENCE :-, How many testicular lobules are found in each testis?, Ans. 250, Name the substance that produced by the seminal vesicle., Ans. Seminal plasma, What term given for the outer cell mass found around the ovum?, Ans. Corona Radiata, What term given for the membrane found around the ovum?, Ans. Zona Pellucida, Where do you found the stem cells?, Ans. Inside of human embryo, along with inner cell mass., What is the term given for the outer layer of the human embryo?, Ans. Trophoblast, What is the ploidy level of the primary oocyte?, Ans. Diploidy, Give the term for the fluid filled cavity of the tertiary foliicular cells., Ans. Antrum, How much sperms must be viable after the ejaculation?, Ans. 60%, What is the term given for the cells of the embryo?, Ans. Blastocysts or blastomere, GIVE THE ANSWER OF THE FOLLOWING QUESTIONS IN 30-50 WORDS., Give the details of the hormonal control over spermatogenesis., Why the parturition is called as nuero endocrinal reflex?, Give the schematic presentation of the spermatogenesis., How it can be proved that a female is a victim of rape?, What are male accessory glands? Give their names and functions., How fraternal twins are different from identical twins?, Give the difference between the spermiogenesis and spermiation., GIVE THE ANSWER OF THE FOLLOWING QUESTIONS IN 70-90 WORDS:-, On the basis of the following diagram, explain the post embryonic development in human embryo., What is the ovarian cycle? Illustrate the ovarian cycle by its all 4 sub stages., What is oogenesis? Describe all stages of oogenesis till the formation of the ovum., READ THE FOLLOWING PARAGRAPH CAREFULLY AND GIVE THE ANSWER OF THE QUESTIONS:-, After implantation, finger like projections appear on the trophoblast called chorionic villi. Which are surrounded by the uterine tissue and maternal blood. The chorionic villi and uterine tissue become interdigitated with each other and jointly form a structural and functional unit between developing embryo (foetus) and maternal body called placenta. Placentas not only supply nutrients and oxygen to the foetus but it also act as endocrine gland. Several hormones called human chorionic gonadotropin, human placental lactogen, estrogens, progesterone etc. produced by placenta to support the pregnancy., Which of the following structure responsible to make the placenta :-, Trophoblast b. inner cell mass c. stem cells d. Amnion, In later stages , to which structure does the trophoblast convert :-, Amnion b. yolk sac c. chrionic villi d. Allantois, Which following structure provide nutrients and oxygen is supplied to the foetus :-, Amnion b. chorionic villi c. Placenta d. none of the above, Which hormone is produced by the placenta :-, Progesterone b. HPL c. HCG d. All of the above, 5 Assertion: - chorionic villi, produced by the trophoblast., Reason: - chorionic villi help to make placenta with uterine tissue., Assertion and Reason, both are correct and reason is the correct explanation of the assertion., Assertion and reason, both are correct but the reason is not correct explanation of the assertion., Assertion is correct and reason is incorrect., Assertion is incorrect and reason is correct., GIVE THE ANSWER OF THE FOLLOWING QUESTIONS IN 30-50 WORDS., Give the details of the hormonal control over spermatogenesis., Why the parturition is called as fetal ejection reflex?, Ans. Foetus creates the first signal for the birth and the signal send to the posterior Pituitary gland and spinal cord. Posterior Pituitary Gland produce hormone called Oxytocin, which give signal to uterus for contractions and simultaneously leads to the birth of the foetus., Give the schematic presentation of the spermatogenesis., How it can be proved that a female is a victim of rape?, Ans. The presence of fructose in the genital tract proves about rape with a female victim., What are male accessory glands? Give their names and functions., Ans. Paired Seminal vesicle, prostate glands, bulbourethral glands are the accessory glands, which produce seminal plasma. Seminal plasma is a thick white fluid which consists of mucus, fructose, calcium, and some enzymes which provide liquid medium to the sperms., How fraternal twins are different from identical twins?, Ans. Fraternal twins born from 2 ova and 2 sperms, identical twins born from 1 ovum and 1 sperm., Give the difference between the spermiogenesis and spermiation., Ans. Spermiogenesis is the release of the young sperms from testis to vasa efferentia and spermiogenesis is the conversion of the spermatid to spermatozoa by sertoli cell., GIVE THE ANSWER OF THE FOLLOWING QUESTIONS IN 70-90 WORDS :-, On the basis of the following diagram, Explain the post embryonic development in human embryo from a to h ., Ans., Diagram a represent the ovum which placed in the ampulla region of oviduct. Outer mass called corona radiate and inner membrane is called Zona Pellucida., Diagram b represents the entry of 1 sperm by acrosome, which release enzyme acrasin that dissolve the layers of ovum., Diagram c represent the cleavage of the zygote , to embryo, Diagram d represent the formation of the new blastocysts or blastomere(embryonic cells), Diagram e represent the 8 celled stage of the embryo called as Morula., Diagram f represent the distinction of the embryo into 2 parts outer layer (trophoblast) and the inner cell mass., Diagram g represent the formation of fluid filled cavity called blastocoels., Diagram h represent the implantation of the embryo inside of the uterine layer or endometrium. (decidua ), What is the ovarian cycle? Illustrate the ovarian cycle by its all 4 sub stages., Ans. It is a monthly cycle of the ovary which found in the primate mammals. The ovarian cycle divided into 4 sub stages:-, Menstruation Phase: - day 1 to day 5. Due to extreme less progesterone, the endometrial layer, clotted blood, mucus, and dead ovum are sloughed off discontinuously., Proliferative Phase or Follicular Phase :- day 6 to day 13 , less progesterone send signals to anterior pituitary to produce LH (Leutinising hormone) , in return to that the LH send signals to the ovary , which make hormone called Estrogen , this hormone develop all the granulose cells and follicular cells and also it repair the damaged layer of endometrium., Ovulatory Phase: - Day 14, at this day the anterior pituitary release LH in maximum quantity, which stimulate the ovulation. The Graafian follicle releases the secondary oocyte, out from the ovary., Luteal Phase: - day 15 to day 28, the remaining mass of follicular cells called Corpus Luteum, secrete hormone Progesterone, which hold, maintain, and repair all stages of fertilization and post fertilization events., What is oogenesis? Describe all stages of oogenesis till the formation of the ovum., Ans. formation of female gamete is called as oogenesis. Following stages are found in oogenesis:-, Formation of Oogonia: - from 3 month of foetal age the epithelium tissue of ovary perform mitosis to produce diploid oogonia cells. No new oogonia produced after birth., Primary Follicular phase: - oogonia perform meiotic division –I, but the meiosis –I is arrested at Prophase –I and mass of follicular cells surrounded the primary oocyte. This stage is called as primary follicular phase. Till puberty 60000-80000 primary follicles are found., Secondary follicular phase: - More number of follicular / granulose cells surrounds the primary oocyte; this structure is called as secondary follicular phase. Granulosa cells divided into outer theca externa and inner theca interna., Tertiary Follicular phase: - now the primary oocyte completed the meiosis –I and converted to 1 secondary oocyte and 1 polar body. And a fluid filled cavity called antrum also get produced inside of the mass of granulosa cells., Graafian follicular phase: - the tertiary follicle mature to form the Graafian follicle, and now the secondary oocyte is surrounded by a new layer called Zona Pellucida. In this phase, the secondary oocyte gets released out from the ovary, which is called ovulation., Corpus luteum: - The remaining mass of the granulosa cells, act as secretory in nature and called corpus luteum, and secrete hormone called progesterone. This is one of the important hormone which support syngamy and pregnancy., READ THE FOLLOWING PARAGRAPH CAREFULLY AND GIVE THE ANSWER OF THE QUESTIONS:-, After implantation, finger like projections appear on the trophoblast called chorionic villi. Which are surrounded by the uterine tissue and maternal blood. The chorionic villi and uterine tissue become interdigitated with each other and jointly form a structural and functional unit between developing embryo (foetus) and maternal body called placenta. Placenta not only supplies nutrients and oxygen to the foetus but it also act as endocrine gland. Several hormones called human chorionic gonadotropin, human placental lactogen, estrogens, progesterone etc. produced by placenta to support the pregnancy., Which of the following structure responsible to make the placenta :-, Trophoblast b. inner cell mass c. stem cells d. Amnion, Ans. Trophoblast, In later stages , to which structure does the trophoblast convert :-, Amnion b. yolk sac c. chrionic villi d. Allantois, Ans. Chorionic Villi, Which following structure provide nutrients and oxygen is supplied to the foetus :-, Amnion b. chorionic villi c. Placenta d. none of the above, Ans. Placenta, Which hormone is produced by the placenta :-, Progesterone b. HPL c. HCG d. All of the above, Ans. All of the above, Assertion: - chorionic villi, produced by the trophoblast., Reason: - chorionic villi help to make placenta with uterine tissue., Assertion and Reason, both are correct and reason is the correct explanation of the assertion., Assertion and reason, both are correct but the reason is not correct explanation of the assertion., Assertion is correct and reason is incorrect., Assertion is incorrect and reason is correct., Ans. Assertion and Reason, both are correct and reason is the correct explanation of the assertion., CHAPETR -4, REPRODUCTIVE HEALTH, ASSERTION REASON TYPE QUESTIONS:-, Read the assertion and the reason and give the answer from the following options (any one):-, Assertion is correct and reason is also correct and the reason is the correct explanation of the Assertion., Assertion is correct and reason is also correct and the reason is not the correct explanation of the assertion., Assertion is correct and reason is not correct., Assertion is in correct and reason is correct., Assertion: - Surgical method of contraception is the permanent method to stop the child birth., Reason: - In surgical method, accessory ducts are cut off and tied., Ans. Assertion is correct and reason is also correct and the reason is the correct explanation of the Assertion., Assertion: - The safest time for MTP is the first trimester., Reason: - The foetus and the mother not yet fully connected with each other., Ans. Assertion is correct and reason is also correct and the reason is the correct explanation of the Assertion., Assertion: - The sexual transmitted diseases, spread by unprotected sexual contacts., Reason: - The microbes of STD primarily found in the genital area, hence reach to another person., Ans. Assertion is correct and reason is also correct and the reason is the correct explanation of the Assertion., Assertion: - Oral pills are the preparation of estrogen-progesterone combinations., Reason: - Such combinations will prevent ovulation, implantation and finally pregnancy., Ans. Assertion is correct and reason is also correct and the reason is the correct explanation of the Assertion., Assertion: - The use of contraceptives is highly recommended to the couples., Reason: - Large families and population create a lot of problems and crisis., Ans. Assertion is correct and reason is also correct and the reason is the correct explanation of the Assertion., READ THE FOLLOWING MCQ QUESTIONS AND CHOOSE THE CORRECT OPTION., In unprotected sex , the chances of pregnancy can be avoided by using the estrogen – progesterone combination with in the duration of, Within 24 hours b. within 48 hours c. within 72 hours d. within 96 hours, Ans. Within 72 hours, How the new oral contraceptive pills – Saheli should be taken by the female users :-, Once in a day b. once in a week c. once in a quarter d. once in a month, Ans. Once in a week, Which method of contraceptive is widely accepted among the females in India :-, Oral contraceptives b. Hormonal implants c. IUDs d. Diaphragm, Ans. IUDs, Which of the following STD caused by virus :-, Gonorrhoea b. Syphlis c. Chlamydiasis d. AIDS, Ans. AIDS, Pelvic Inflammatory diseases is found among :-, Males b. Females c. Children d. Elderly ages people, Ans. Females, GIVE THE ANSWERS OF FOLLOWING QUESTIONS IN 1 WORD OR 1 SENTENCE:-, What is the full form of ZIFT and GIFT?, Ans. Zygote Intra Fallopian Transfer and Gamete Intra Fallopian Transfer, What is the term used for the cut off the fallopian tube followed by tied up of this?, Ans. Tubectomy, Name two hormone releasing IUDs., Ans. LNG – 20 and Progestasert, Expand RCH., Ans. Reproductive and child healthcare Programme, Where the Central Drug Research Institute is located?, Ans. Lucknow, At which year the family planning programme initiated?, Ans. 1951, A doctor performed Amniocentesis of a pregnant mother and suggested to the mother to do the MTP. What should be the reason behind this suggestion?, Ans. In the germ cells of foetus, there was a chromosomal abnormality reported, so after amniocentesis the doctor advised to MTP., In ET techniques, where does the embryo get transferred in the female’s reproductive system?, Ans. If the embryo implanted in 8 celled stages, then it transferred in the fallopian tube, and if the embryo implanted in 32 celled stage, then it transferred to the uterus., How condoms act as barriers?, Ans. A condom, retain the semen and not allow the semen to eject in the female genital tract, by this way the condom act as barrier., Upto how long the lactation amenorrhea, can work as natural method of contraceptives?, Ans. 6 months, GIVE THE ANSWER OF THE FOLLOWING QUESTIONS IN 30 – 50 WORDS:-, A mother want to pace between the birth of 2 children, and her doctor advised to take copper – T. Enumerate how this work as contraceptive?, Ans. Copper – T is an IUD type contraceptive and it placed inside of the uterus, after placing it continuously produce cu+ ions or cupric ions in the uterus, which are phagocytic in nature for the sperms, cupric ions also suppress the sperm motility and fertilizing capacity of the sperms., What is the surgical method of contraception? Give its two types., Ans. Surgical method of contraception is a permanent method also called as Sterilization. In male the Vas deferens is cut off and tied , and in females the oviduct or fallopian tube cut off and tied., A female wants to use Saheli as oral contraceptives, how this pill will be effective on the female?, Ans. Saheli is an oral pill which is the estrogen – progesterone combination. They inhibit the ovulation and implantation; also alter the quality of the cervical mucus to prevent the entry of the sperm through the cervical region., Name 2 bacterial caused and 2 viral caused STDs .and the mode of prevention., Ans. Bacterial STD: - Gonorrhea, Syphilis Viral STDs: - Genital Herpes, AIDS, Sexually transmitted diseases can be prevented by following precautions:-, Avoid sexual contact with multiple partners/unknown partners, Always try to use the barriers like condom during coitus., One should go to the well qualified doctor, for early detection and get complete treatment., Give the full form and meaning of IMR and MMR. When does the risks of IMR and MMR become greater?, Ans. IMR – Infant Mortality Rate, Death of the young children in a unit area in the unit time period is called IMR., MMR – Maternal Mortality Rate, Death of the female either during gestation or after the child birth is called MMR., When proper vaccination, or lack of nutritional supplements or unhygienic parturition are some reason for the deaths of infants and mothers., GIVE THE ANWER OF THE FOLLOWING QUESTION IN 50-70 WORDS:-, What is the natural method of contraception? Describe its all 3 methods., Ans. When child birth is prevented without using any device, such birth control of child is called natural method of contraception. Following are the 3 types of the natural methods:-, Lactational Amenorrrhea: - from the birth of the foetus up to the 6 months, due to intense lactation, the anterior Pituitary not secrete LH and FSH. As a result the ovulation process also gets stopped, hence the chances to get pregnant become nil., Periodic Abstinence: - In this method the couple needs to avoid or abstain coitus from day 10 to day 17, since in this duration the ovulation is highly expected. So by avoiding coitus the contraception can be maintained., Coitus Interruptus: - In this method the male partner need to withdraw or remove the genital organ from female’s gentiles just before the ejaculation. By this way the chances of the child birth can be avoided., What is ZIFT and GIFT? Give the stages of both the methods., Ans. ZIFT :- Zygote Intra Fallopian Transfer :- it is also called test tube baby programme , in which the ovum from the wife or donor female and the sperms from husband or donor male is taken in a test tube and allowed to divide. In early embryonic development (8 celled stage ) the embryo transferred to the fallopian tube , and in late embryonic development stages (32 celled stage embryo) , the embryo transferred to the uterus. Sometime the embryo from real mother also transferred to the uterus /fallopian tube of the female who cannot conceive..., GIFT: - Gamete Intra Fallopian Transfer: - it the transfer of the female gamete or ovum to the fallopian tube of the female who cannot conceive followed by syngamy naturally or by AI. The ovum is collected from the donor female., What is amniocentesis? Write its one merit and its one demerit., Ans. Testing or examination of the chromosomes in the germ cells of amniotic fluid is called Amniocentesis. Its advantage is, it help to detect the chromosomal anomaly like sickle cell anemia, haemophilia, Down syndrome etc., Its disadvantage is the female foeticide, or induced death of the female foetus before birth., What is the venereal disease? Give the 4 names of venereal diseases with general symptoms., Ans. Sexually Transmitted Diseases are called as venereal diseases. Names of 4 venereal diseases are Gonorrhoea, Syphilis, Chlamydiasis, Hepatitis –B, Genital Herpes etc., General symptoms of STDs are itching, pain, unusual menstruation, white discharge, irritation while urination, loss of fertility, PID (Pelvic Inflammatory Disease), still birth, abortions, ectopic pregnancies etc., What is emergency contraceptive? How it can be administered in a female?, Ans. If intercourse is done in unprotected way, in such condition the chances of pregnancy become greater, and then if a contraceptive device is applied, such a contraceptive is called emergency contraceptive., Progesterone alone or estrogen – progesterone combinations can be used as IUD or pills as emergency contraceptives. They need to be taken within 72 hours from the coitus. It prevent the ovulation and implantation, hence the contraceptive purpose is attained., READ THE FOLLOWING PARAGRAPH AND GIVE THE ABSWER OF THE FOLLOWING QUESTIONS:-, Intentional or Voluntary termination of the pregnancy before full terms is called medical termination of pregnancy (MTP) or induced abortion. Nearly 45 to 50 million MTPs are performed in a year all over the world which accounts to 1/5th of the total number of conceived pregnancies in a year. Whether to accept / legalise MTP or not is being debated upon in many countries due to emotional , ethical , religious , and social issues involved in it. Government of India legalized MTP in 1971 with some strict conditions to avoid its misuse. Such restrictions are all the more important to check indiscriminate and illegal female foeticides which are reported to be high in India. MTPS are considered as relatively safe during the first trimester or up to 12 weeks of pregnancy., In which year the MTP is legalized by Indian Government :-, 1970 b. 1971 c. 1972 d. 1973, Ans. 1971, How many MTPs are reported in entire world in a year :-, 40 to 45 million b. 45-50 million c. 50-55 million d. 55-60 millions, Ans. 45 – 50 millions, The destruction of a female foetus , before birth is called, Abortion b. MTP c. female foeticide d. Miscarriage, Ans. Female Foeticide, At what time the MTP is considered as safe:, In first week b. in first quarter c. in first trimester d. in first month, Ans. In the first trimester, Assertion: - Indian Government allow MTPs under some restricted conditions., Reason: - Some foetus has genetic disorders and has retarded development., Which one of the following will be the correct answer for this question:-, Assertion is correct and reason is also correct and the reason is the correct explanation of the Assertion., Assertion is correct and reason is also correct and the reason is not the correct explanation of the assertion., Assertion is correct and reason is not correct., Assertion is in correct and reason is correct., Ans. Assertion is correct and reason is also correct and the reason is the correct explanation of the Assertion., CHAPTER 5 -PRINCIPLES OF INHERITANCE AND VARIATIONS, DEFINITIONS-, 1. HEREDITY- It is the transmission of characters from parents to offsprings., 2. INHERITANCE- It is the process by which characters or traits pass from one generation to the next., 3. CHARACTERS- It is well defined morphological or physiological feature of the individual.eg. Stem height., 4. TRAIT- It is distinguishable feature of a character.eg. Tallness/dwarfness., 5. ALLELE- The two Mendelian factors which occur on the same locus in the two homologous chromosomes of an individual and control the expression of a character., 6. HOMOZYGOUS- It is pure for a trait and breeds true or give rise to similar homozygous individuals., 7. HETEROZYGOUS- It is seldom pure and produces offsprings with different genotypes., 8. TEST CROSS- It is a cross to know whether an individual is homozygous or heterozygous for dominant character., 9. PURE LINE- It is a strain of genetically pure true breeding individuals which have been derived from a single self-fertilized homozygous ancestor ., 10. GENOME- It is a complete set of chromosomes where every gene and chromosomes is represented singly as in a gamete., 11. LINKAGE- Physical association of genes on a chromosomes., 12. RECOMBINATION- Generation of non-parental gene combination arising from crossing over between non-homologous chromosomes., MCQ, 1. If a plant heterozygous for tallness is selfed, the F2 generation has both tall and dwarf plants. It proves the principle of-, (a) Dominance (b) segregation (c) independent assortment (d) incomplete dominance., 2. What will never be father’s blood group if the mother has blood group B and child blood group O?, (a) A (b) B (c) AB (d) O, 3. Sickle cell anemis is the example of:-, a. Point mutation b. frame shift mutation c. Hatch back mutation d. none of these, 4. A child has blood group O. If the father has blood group A and mother blood group is B. then what will be the blood group of the other children:-, a. A,& B b. A & B & AB c. B & AB d. not determined, 5. Haemophilia is fall in the category of :-, a. Autosomal recessive disorder b. autosomal dominant disorder, c. x- linked recessive disorders d. x- linked dominant disorder, ASSERTION-REASON QUESTIONS, In the following questions a statement of assertion followed by a statement of reason is given. Choose the correct answer out of the following choices., Assertion and reason both are correct statements and reason is correct explanation for assertion., Assertion and reason both are correct statements but reason is not correct explanation for assertion., Assertion is correct statement but reason is wrong statement., Assertion is wrong statement but reason is correct statement., 3. Assertion: Mendel successfully conducted his hybridization experiments., Reason: Garden pea was an ideal experimental material., 4. Assertion: Down’s syndrome is caused due to absence of either X or Y sex chromosome., Reason: Such individuals show mental retardation and broad head with characteristic features., VSA(1 MARKS), 5. Name the type of cross that would help to find the genotype of a pea plant bearing violet flowers. ( CBSE/AI 2017)., 6.A male honeybee has 16 chromosomes whereas its female has 32 chromosomes. Give one reason. ( CBSE/AI/2016)., SA( 2 MARKS), 7.During monohybrid cross involving a tall pea plant with a dwarf pea plant, the offspring population were tall and dwarf in equal ratio. Work out a cross to show how it is possible.(CBSE/AI/2015)., 8.What is a test cross? How can it decipher the heterozygosity of a plant?(CBSE/AI/2016)., 9.Both haemophilia and thalassemia are blood related disorders in human. Write their causes and the difference between the two. Name the category of genetic disorder they both come under. (CBSE/AI/2017)., 10.What happens when chromatids fail to segregate during cell division cycle ? Explain your answer with an example., OR, ABO blood groups is a good example of co-dominance. Justify( CBSE/AI/COMP/2018), SA( 3 MARKS), 11. Explain the mechanism of ‘sex determination’ in birds. How does it differ from that of human beings ?(CBSE/AI/2018), 12.(a) How does mutation occur?, (b) Differentiate between point mutation and frame shift mutation.( CBSE/AI/2019), 13.A cross is made between different homozygous pea plant for contrasting flower positions.(CBSE/2015/2017), (a) Find out the position of flowers in F1 generation on the basis of genotypes., (b) Work out the cross up to F2 generation., (c ) Compute the relative fraction of various genotypes in the F2 generation., 14 How is polygenic inheritance different from Pleiotropy? Give one example of each ..(CBSE/AI/COMP/2019), LA( 5 MARKS), 15.a) Write the scientific name of the organism Thomas Hunt Morgan and his colleagues worked with for their experiments. Explain the correlation between linkage and recombination with respect to genes as studied by them. (b) How did Sturtevant explain gene mapping while working with Morgan? (CBSE/AI/2018), 16. (A) Explain Polygenic inheritance and multiple allelism with the help of suitable examples., (b) “Phenylketonuria is a good example that explains Pleiotropy. Justify. (CBSE/AI/2017)., ANSWERS, 1. (B)., 2. C., 3. (B), 4. (D), 5. Test cross., 6. Male honeybee develops from unfertilized female gamete by Parthenogenesis whereas females develop by fertilization., 8. A cross to analyse whether genotype of dominant individual is homozygous or heterozygous is called test cross., On crossing with a recessive parent, if 50% of progeny have dominant trait and 50% have recessive trait then the parent is said to be heterozygous., 9., 10. It results in an increase in whole set of chromosomes in an organism. It is polyploidy and often seen in plants., OR, The alleles which are able to express themselves independently even when present together are codominant alleles and this phenomenon is co-dominance., IA& IBare dominant and produces RBC surface antigens which are sugar polymers A & B resp. When they are present together, both express equally., 11. In birds, female heterogamety is observed. They exhibit ZW type of sex determination., Parents ZZ ZW, Gametes Z Z W, Progeny, ZZ (male) ZW (female)., In human, males heterogamety is observed., 12. (a) Mutation occurs due to change in base pairs on DNA., (b) Point mutation arises due to change in single base pair of DNA. Frame shift mutation occurs due to insertion or deletion of base pairs., 13. (a) Axial position., (b) Parental AA aa, Gametes A a, F1 generation Aa, Selfing, F2 Aa Aa, ( c) AA= ¼, Aa= ½, aa= ¼., 14 Polygenic inheritance a) A single trait influenced by many genes, b) e.g height/ skin colour in humans controlled by three or more genes., Pleiotropy a) A single gene can exhibit multiple phenotypic expression = 2, b) e.g phenylketonuria ,characterised by mental retardation / reduction in hairs and / skin pigmentation / or any other correct example = ½+½, CHAPTER: 6 MOLECULAR BASIS OF INHERITANCE, KEYPOINTS:, Easy and Scoring Topics, Structure of Polynucleotide chain and salient features of DNA double helix, Structure of Nucleosome (Labelled Diagram), Difference between Euchromatin and heterochromatin., Characteristics of the Genetic material., Diagram of replication fork with correct polarity and labelling., Diagram of transcription unit with correct polarity, Difference between gene arrangement in prokaryotes and eukaryotes (Polycistronic, monocistronic, split gene arrangement.), Processing of hnRNA (Capping, tailing and splicing), Characteristics of Genetic code:, Diagram of tRNA., Diagram of lac operon in the presence and absence of lactose., Experiments related to the search of genetic material and Mode of DNA replication:, HGP, Method and Basis of DNA Fingerprinting, FREQUENTLY ASKED QUESTIONS:, VSA (One Mark Questions), Q1. Name the specific components and the linkage between them that form deoxyadenosine, Q2.Name the components A and B in the nucleotide with a purine, given below, Q3.Mention the carbon positions to which nitrogenous base and the phosphate molecule are respectively linked in the nucleotide given below., Q 4. Name the positively charged protein around which the negatively charged DNA wrapped., Q5. RNA is more reactive than DNA. Why?, Q6.Study the given portion of double stranded polynucleotide chain carefully. Identify A, B, C and the 5′ end of the chain, Q 7. What will happen if DNA replication is hot followed by cell division in a eukaryotic cell?, Q8. Name the enzyme involved in continuous replication of DNA strand. Mention the polarity of the template strand., Q 9. A structural gene has two DNA strands X and Y shown below. Identify the template strand., Q 10. Name the type of synthesis A and B occurring in the replication fork of DNA as shown below., Q11. Mention the polarity of the DNA strands A-B and C – D shown in the replicating fork given below., Q 12. Which one out of rho factor and sigma factor act as an initiation factor during transcription in a prokaryote?, Q 13. Name the parts A and B of the transcription unit given below., Q 14. What are A and B in the transcription unit represented below?, Q 15. Why is hnRNA required to undergo splicing?, Q 16. Mention the two additional processes, which hnRNA needs to undergo after splicing so, as to become functional., Q 17. When and at what end the tailing of hnRNA does takes place?, Q 18. Give an example of point mutation., Q 19. Name one amino acid, which is coded by only one codon., Q 20. Mention the Dual role of AUG., Q 21. Write the two specific codons that a translational unit of mRNA is flanked by on either sides., Q 22. State which chromosomes has the maximum number of genes and the one which has the least number of genes., Q 23. Write the scientific importance of single nucleotide polymorphism identified in human genome., SA I (Two Marks Questions), Q24.Answer the questions based on the dinucleotide shown below, (i)Name the type of sugar guanine base is attached to., (ii)Name the linkage connecting the two nucleotides., (iii)Identify the 3′ end of the dinucleotide. Give a reason for your answer., Q25. Make a labelled diagram of an RNA dinucleotide showing its 3′ ->5′ polarity., Q26. Explain the two factors responsible for conferring stability to double helix structure of DNA., Q27. A DNA segment has a total of 2000 nucleotides, out of which 600 are thymine. How many pyrimidine bases are present in this DNA segment?, Q28. Draw a labelled diagram of a nucleosome. Where is it found in a Cell?, OR, How do histones acquire positive charge?, Q29. Give one function each of histone protein and non-histone chromosomal protein in a eukaryotic nucleus., Q 30. Show DNA replication with the help of a diagram only., Q 31. Compare the roles of the enzymes DNA polymerase and DNA ligase in the replication fork of DNA, Q 32. Write the dual purpose served by deoxyribonucleoside triphosphates in polymerisation, Q 33. Differentiate between a template strand and a coding strand of DNA., Q 34. Describe the initiation process of transcription in bacteria., Q 35. State the difference between the structural genes in a transcription unit of prokaryotes and eukaryotes., Q 36. The arrangement of structural genes in transcriptions unit is not similar in prokaryotes and eukaryotes. Explain., Q 37. What do you mean by the following properties of genetic code?, Unambiguous, degenerate, Universal codon, Stop codon, Q 37. How does the presence of lactose in the medium activate the lac operon?, Q 38. Explain aminoacylation of tRNA., Q 39. Enlist the two methodologies used for sequencing human genome in HGP. How they were used?, Q 40. Expand BAC and YAC. What is the purpose for which they are used?, Q 41. Mention any two applications of DNA fingerprinting, Q 42. Explain the importance of satellite DNA in DNA fingerprinting technique., Q 43. Expand VNTR and describe its role in DNA fingerprinting., SA II (Three Marks Questions), Q44. Draw a schematic representation of a dinucleotide. Label the following., (i) The component of a nucleotide, (ii) 5′ end, (iii) N-glycosidic linkage, (iv)Phosphodiester linkage, Q45. List the salient features of double helix structure of DNA., Q46. The length of a DNA molecule in a typical mammalian cell is calculated to be approximately 2.2 m. How is the packaging of this long molecule done to accommodate it within the nucleus of the cell?, Q47. It is established that RNA is the first genetic material. Explain giving three reasons., Q48. Why DNA is considered a better hereditary material than RNA?, Q49. List the characteristics that must be fulfilled by the genetic material., Q50. Why do you see two different types of replicating strands in the given DNA replication fork? Explain. Name these strands., Q 51. (i) why does DNA replication occur in small replication fork and not in its entire length?, (ii) Why is DNA replication continuous and discontinuous in a replication fork?, (iii) Explain the importance of origin of replication in a replication fork., Q 52. (i) Explain the process of DNA replication with the help of a schematic diagram., (ii) In which phase of the cell cycle does replication occur in eukaryotes? What would happen if cell division is not followed after DNA replication?, Q 53. With the help of a schematic diagram, explain the location and role of the following in a transcription unit. Promoter structural gene, terminator., Q 54. (i) Draw a schematic representation of transcription unit showing the polarity of both the strands. Label the promoter gene and the template strand., (ii) Mention the condition when template strand becomes coding strand., (iii) Give the function of the promoter gene., Q 55. (i) What are the transcriptional products of RNA polymerase III?, (ii)Differentiate between ‘capping’ and ‘tailing’., (iii) Expand hnRNA., Q 56. How is hnRNA processed to form mRNA?, (i) Name the enzyme that catalyses the transcription of hnRNA., (ii) Why does the hnRNA needs to undergo changes? List the changes hnRNA undergoes and where in the cell such changes take place., Q 57. Draw a schematic representation of lac operon in its switched off position. Label the following:, The structural genes, Repressor bound to its correct position, Promoter gene, Regulatory gene, Q 58. (i) Name the scientist who called tRNA an adapter molecule., (ii)Draw a clover leaf structure of tRNA showing the following:, Tyrosine attached to its amino acid site., Anticodon for this amino acid in its correct site (codon for tyrosine is UAC), (iii) What does the actual structure of tRNA look like?, Q 59. In a series of experiments with Streptococcus and mice, F Griffith concluded that R-strain bacteria had been transformed. Explain., Q 60. Describe the technique of DNA Fingerprinting., OR, A number of passengers were severely burnt beyond recognition during a train accident. Name and describe a modern technique that can help handover the dead to their relatives., LA (Five Marks question), Q61. (i) State the central dogma in molecular biology. Who proposed it? Is it universally applicable? Explain., (ii) List any four properties of a molecule to be able to act as a genetic material., Q 62. Describe the process of transcription in bacterium., Q 63. Draw the labelled schematic structure of a transcription unit. Explain the function of each component of the unit in the process of transcription., Q 64. (i) Describe the various steps of Griffith’s experiment that led to the conclusion of the ‘transforming principle’., (ii)How did the chemical nature of the ‘transforming principle’ get established?, Q 65. Describe the Hershey and Chase’s experiment. Write the conclusion drawn by the scientists after their experiment, OR, Name the scientists, who proved experimentally that DNA is the genetic material. Describe their experiment., Q 66. (i) What did Meselson and Stahl observed? When , (a) They cultured coli in a medium containing 15 NH4 Cl for a few generations and centrifuged the content?, (b)They transferred one such bacterium to the normal medium of NH4 Cl and cultured for two generations., (ii)What did Meselson and Stahl conclude from his experiment? Explain with the help of diagrams., (iii)Which is the first genetic material? Give reasons in support of your answer., SAMPLE QUESTIONS, MULTIPLE CHOICE QUESTIONS:, if the sequence of nitrogen bases of the coding strand of DNA in a transcription unit is: 5’ – ATGAATG – 3’, the sequence of bases in its RNA transcript would be:, (a) 5’ – AUG A AUG – 3’, (b) 5’ – UACUU AC – 3’, (c) 5’ – CAUUCAU – 3’, (d) 5’ – GUAAGUA – 3’., The amino acid attaches to the tRNA at its, (a) 5’- end , (b) 3’ – end, (c) anticodon site , (d) DHU loop., 3. Synthesis of DNA from RNA is explained by, (a) central dogma reverse, (b) reverse transcription, (c) feminism, (d) all of these., 4. The process of transformation is not affected by which of the following enzymes?, A. DNase, B. RNase, C. Peptidase, D. Lipase, (a) A, B, (b) A, B, C, D, (c) B, C, D, (d) A, B, C, 5. Assertion: The DNA strand having polarity 3’-5’ replicated continuously whereas the strand with polarity 5’- 3; replicated discontinuously., Reason: The DNA polymerase catalyses the polymerisation only in one direction., Both assertion and reason are true and reason in the correct explanation of assertion, Both assertion and reason are true but reason is not the correct explanation of assertion, Assertion in correct but the reason is incorrect, Assertion is incorrect but the reason is correct, 6. Assertion: In Prokaryotes the DNA is localised at the specific place in the cytoplasm called nucleoid., Reason: Histone proteins play an important role in the packaging of DNA., Both assertion and reason are true and reason in the correct explanation of assertion, Both assertion and reason are true but reason is not the correct explanation of assertion, Assertion in correct but the reason is incorrect, Assertion is incorrect but the reason is correct, 7. Assertion: VNTRs are used as probes for hybridisation in DNA Fingerprinting., Reason: DNA fingerprinting is based on the principle of Polymorphism in DNA sequences., Both assertion and reason are true and reason in the correct explanation of assertion, Both assertion and reason are true but reason is not the correct explanation of assertion, Assertion in correct but the reason is incorrect, Assertion is incorrect but the reason is correct, 8. Assertion: Absence of 32P radioactivity in the supernatant proves that DNA is the genetic material., Reason: DNA contains phosphorus but proteins does not., Both assertion and reason are true and reason in the correct explanation of assertion, Both assertion and reason are true but reason is not the correct explanation of assertion, Assertion in correct but the reason is incorrect, Assertion is incorrect but the reason is correct, Mention the function of RNA polymerase II., What is the role performed by the following during transcription in prokaryotes: i. Sigma factor ii.Rho Factor, Name the enzyme involved in the discontinuous replication of DNA. Mention the direction of replication., Define satellite DNA., The arrangement of structural genes in transcriptions unit is not similar in prokaryotes and eukaryotes. Explain., . What do you mean by the following properties of genetic code?, (i)Unambiguous, (ii) degenerate, (iii) Universal codon (iv) Stop codon, 15. A DNA segment has a total of 1600 nucleotides, out of which 580 are thymine. How many pyrimidine bases are present in this DNA segment?, 16. Draw a schematic representation of lac operon in its switched off position. Label the following:, The structural genes, Repressor bound to its correct position, Promoter gene, Regulatory gene, 17. (a) Draw a neat labelled diagram of a nucleosome?, (b) What makes histones positively charged?, 18. Answer the following questions based on the experiment that proved that DNA replication is semiconservative., Name the scientist who performed this experiment and the chemical substance used by them as the source of nitrogen., Identify the method used to separate heavy DNA from the light DNA., What will be the results after 20 and 40 minutes of experiment?, 19. Answer the following questions based on the Hershey and Chase’s experiment, (a) Name the viruses they worked on and why the viruses are called so?, (b) Why did they use the two different radioactive substance in the culture medium to grow viruses?, (c) What was the need of the blender in the experiment?, (d) State the conclusion drawn by them after the experiment., 20. (a) Describe the experiment which indicates the existence of transforming principle., (b) How did the biochemical nature of the transforming principle get established?, ANSWER KEY, CHAPTER 8 HUMAN HEALTH AND DISEASES, VERY SHORT ANSWER QUESTIONS (1 MARKS), Malaria, typhoid, pneumonia and amoebiasis are some of the human infectious disease. Which ones of these are transmitted through mechanical carriers?, Ans: Malaria and amoebiasis are transmitted through mechanical carrier., Name the two intermediate hosts which the human liver fluke depends on to complete its life cycle so as to facilitate parasitisation of its primary host., Ans: Snails and fish, How does haemozion affect the human body when released in the blood during malarial infection?, Ans: Haemozoin is responsible for the chill and high fever recurring every three to four days during malarial infection., State two different roles of spleen in the human body., Ans: Spleen is the secondary lymphoid organ that stores lymphocytes, if filters microbes and acts as a reservoir to store erythrocyte (any two), A boy of ten years had chicken pox. He is not expected to have the same disease for the rest of his life. Mention how it is possible., Ans: The boy when encounters a pathogen for the first time, his body produces antibodies that result is the memory of the first encounter, to protect the body in future, Thymus of a new born child was degenerating right from birth due to a genetic disorder. Predict its two impacts on the health of the child., Ans: Thymus provides micro-environment for the development and maturation of T-lymphocytes. Its degeneration will weaken the immune system so the child will be prone to frequent infections., Why is secondary immune response more intense than the primary immune response in humans?, Ans: This is because od presence of antibodies developed during primary., Retroviruses have no DNA. However, the DNA of the infected host cell does posses viral DNA. How is it possible?, Ans: On infecting the host cell, the viral RNA transforms into viral DNA by reverse transcription. This viral DNA then incorporates into host DNA., Mention the usefull as well as the harmful drug obtained from the latex of poppy plant., Ans: Useful drug- morphine, harmful drug- heroin., Why sharing of infection needle between two individuals is not recommended?, Ans: Sharing of needle can transmit disease like HIV, AIDs, Hepatitis B or C from infected to non-infected individuals., There are some chemicals that cause cancer name the term used for them., Ans. Carcinogens, Which disease is confirmed by Widal Test? Name the pathogen., ANS- Typhoid, Salmonella typhi., What are interferons?, ANS- Proteins secreted by virus infected cells, non infected cells are protected from viral infections, SHORT ANSWER QUESTION (2 MARKS), Identify a ,b ,c and d in the following table:, Why is the person with cuts and bruises following an accident administered tetanus antitoxin?, Ans: Tetanus is caused a microbe which has a deadly and fast action. Action of vaccine is slow and this delay may become fatal. Therefore, antitoxins are administered which neutralise the effect of the bacterial toxin., Name the two types of immune system in a human body. Why are cell-mediated and humoral immunities so called?, Ans: The two types of immune systems in human body are innate and adaptive immunity is called so because it consists of antibodies that are present in humors or body fluids, whereas cell-mediated immunity is provided by T-cells and defends body against virus, fungi and some bacteria which enter host cells. T-cells recognise non-self-cells and kill them., What is colostrum? Why is it important to be given to the new born infants?, Ans: The milk that comes out of the mammary glands during initial days of lactation is called colostrum. It is contains several antibodies (IgA most abundantly), absolutely essential for the developing resistance in the new born babies., Certain diseases are spread by mosquitoes and two such diseases are spread by a mosquito which bites in the day time. Both the diseases are caused by viruses., a) Name the mosquito., b) Name the diseases with one symptom of each., Ans. a) Aedes, c) dengue: muscle pain, chickungunya: very high fever, A child gets colostrum and polio drop both as an infant. Compare their mode of action with respect to our immune system., Ans. Colostrum provides passive immunity to child, polio drop/vaccine provides active immunity., Write the specific symptoms of pneumonia. Name the causative organism., ANS- Fever, chill, headache .In severe case lips & finger nails may turn bluish., Streptococcus pneumonia & Haemophilous influnzae, SHORT ANSWER QUESTION (3 MARKS), (a) Name the causative agent of typhoid in humans., (b) Name the test administered to confirm the disease., (c) Mention two symptoms common to both., ANS: (a) Pneumonia is caused by streptococcus pneumiae/ Haemophilus influenzae and that of common cold is Rhinovirus, (b) Different symptoms:, (c) Common symptoms:, (i) In both the cases the infected person is inflicted with cough., (ii) in both the cases the patient suffers from headaches., The immune system of a person is suppressed. In the ELISA test, he was found positive to a pathogen., Name the disease the patients is suffering from., What is the causative organism?, Which cells of the body are affected by the pathogen?, Ans: a) The disease is AIDs, b) Explain the response of the body to an allergen., c) It affects or destroys helper T-cells., The property of “Memory” is observed in computers. Can you relate the same property to vaccination and immune system?, Ans- In vaccination, vaccines generate memories.-B-and T-cells recognise the pathogen quickly and invade with the massive production of antibodies., . Fill in the spaces/ blanks in the following flow chart., (i) Mosquito bites a healthy human and injects sporozoites., (ii) Sporozoites reach the ____a______ through __b_____, (iii) Reproduces ____c_________ burst the cells and release into blood, (iv) Enter the ____d______, (vi) Some of them form ____e____ that are picked up by a mosquito when it bites., ANS- a. liver, b. blood, c. asexually, d. haemozoin, e. gametocytes., LONG ANSWER QUESTION (5 MARKS), (a) Name and explain giving reasons, the types of immunity provided to the new born by the colostrum and vaccinations., (b) Name the type of antibody, (i) Present in colostrum, (ii) Produced in response to allergens in human body., Ans: (a) Colostrum provides passive immunity, because the infant gets antibodies from the mother’s body directly for protection. Vaccination provides active immunity active because in the case microbes are injected into the body do develop immunity slowly., (b) (i) IgA (ii) IgE, (a) cancer is one of the most dreaded disease of humans. Explain ‘Contact inhibition’ and ‘Metastasis’ with respect to the disease., (b) Name the group of genes which have been identified in normal cells that could lead to cancer and how they do so?, (c) Name any two techniques which are useful to defect cancers of internal organs., (d) Why are cancer patients often given α-interferon as part of the treatment?, Ans: (a) Contact inhibition is the properly of normal cells in which contact with order cells inhibits their uncontrolled growth., Metastasis is the property in which tumour cells reach distant sites in the body, through blood., (b) Proto oncogenes or Cellular oncogenes., These genes when activated under certain condition could lead to oncogenic transformation of the cells., (c) Biopsy/radiograph/CT/MRI (Any two), (d) α-interferon activities immune system and destroys the tumours., Write the source and the effect on the human body of the following drugs:, (i) Morphine, (ii) Cocaine, (iii) Marijuana, ANS-. (i) Morphine: It is obtained from poppy plant Papaver somniferum. It binds to specific opioid receptors present in central nervous system and gastrointestinal tract., (ii) Cocaine: It is obtained from coca plant Erythroxylum coca. It interferes with the transport of the neurotransmitter dopamine., (iii) Marijuana: It is obtained from Cannabis sativa. It affects the cardiovascular system of, the body., ASSERTION-REASON QUESTION:, In the following question a statement of assertion followed by a statement of reason is given. Chosen the correct answer out of this following choice:, Assertion: Interferons are glycoproteins which are produced by virally infected cells., Reason : Interferons stimulate inflammation at the site of injury., Assertion and reason both are correct statements and reason is correct explanation for assertion., Assertion and reason both are correct statement but reason is not correct explanation for assertion., Assertion is correct statement but reason is wrong statement, Assertion is wrong statement but reason is correct statement, ANS: (c), Assertion : Tapeworm, roundworm and pinworm are endoparasite of human intestine., Reason : Improperly cooked food is the source of intestinal infections., Assertion and reason both are correct statements and reason is correct explanation for assertion., Assertion and reason both are correct statement but reason is not correct explanation for assertion., Assertion is correct statement but reason is wrong statement, Assertion is wrong statement but reason is correct statement, ANS: (b), Assertion : Mast cells in the human body release excessive amounts of inflammatory chemicals certain individual., Reason : Allergens in the environment on reaching human body stimulate mast cells in certain individual, Assertion and reason both are correct statements and reason is correct explanation for assertion., Assertion and reason both are correct statement but reason is not correct explanation for assertion., Assertion is correct statement but reason is wrong statement, Assertion is wrong statement but reason is correct statement, ANS: (c), Assertion: Tobacco contains nicotine which stimulate the adrenal gland., Reason : Nicotine increase the blood pressure and the heavy rate., Assertion and reason both are correct statements and reason is correct explanation for assertion., Assertion and reason both are correct statement but reason is not correct explanation for assertion., Assertion is correct statement but reason is wrong statement, Assertion is wrong statement but reason is correct statement, ANS: (b), Assertion : Opioids helps to enhance respiratory activity., Reason : Opioids bind to the receptors in the central nervous system and gastrointestinal, Assertion and reason both are correct statements and reason is correct explanation for assertion., Assertion and reason both are correct statement but reason is not correct explanation for assertion., Assertion is correct statement but reason is wrong statement, Assertion is wrong statement but reason is correct statement, ANS: (d), DIAGRAM BASED QUESTION, Identify the molecule and name A, B and C in the figure, Ans. A= antigen binding site, B= Heavy chain, C= disulphide bonds., 2. Identify the plant and name the drug obtain from this plant., Ans. Opium (Papaver somniferum), morphine., 3. Which type of mode of reproduction is visible in the following figure also mention in which host of Plasmodium does this process take place?, Ans. Plasmodium undergoes multiple fission in the liver cells and erythrocytes of human host., 4. Identify and label the X, B and C in the following figure., Ans. X= Viral RNA , B= formation of DNA from RNA by enzyme reverse transcriptase, C= Viral DNA, 5. Which type of immunity is depicted by the following figure, also explain the plasma B cell formation from naïve B cell?, Ans. Antibody mediated immunity or humoral immunity, the naïve B cell gets signal from helper T cell and then transforms into plasma or secretory cells., 6. Identify the organism shown in the picture below. Mention the name of disease it causes, and any two symptoms of that disease., Ans. Ascaris/Roundworm, Causes ascariasis, symptoms: abdominal pain, fatigue., 7. The diagram shows the life cycle of the pathogen causing a human disease., a) Name the pathogen, Disease and vector., b) Label the stages 1 to 9, Ans. a) Plasmodium, Malaria, female Anopheles mosquito, b) 1.Sporozoite migrate to salivary glands, 2.Sporozoites reach liver, 3. Asexually reproducing in liver cell, 4. Infection of new RBCs, 5. Sexual stage in RBCs, 6. Formation of male and female gametocytes, 7. Female mosquito ingests gametocytes with blood, 8. Fertilization in mosquito intestine, 9. Formation of sporozoites from oocyte., CHAPTER 10 MICRBES IN HUMAN WELFARE, (1 MARK), Q1 Which one of these is a proteineceous infecting agent ?, a)Viroids b)prions c)Protein d)fat, ANS----b), Q.2 Which of these is/are symbiotic N2 fixing organisms?, a) Rhizobium b) Clostridium c)Azotobacter d) All of these, ANS----a), Q.3 Methanogens do not produce, a)Oxygen b)Methane c) Hydrogen sulphide d) Carbon dioxide., ANS-----a), Q.4 The free-living fungus Trichoderma can be used for., a) Insect b) Biological control of plant disease c) Controlling butterfly caterpillars, d) producing antibiotics, ANS----b), Q.5 Big holes in Swiss cheese are made by, a) A Machine b) A bacterium that produces methane gas, c) A bacterium producing a large amount of carbon dioxide, d) A fungus that release a lot of gases during its metabolic activities., ANS---c), VERY SHORT ANSWER QUESTION(1 MARK), Q.1What causes doughing of wheat flour?, ANS--- Production of CO2 gas during yeast fermentation of bacteria., Q.2 Write the scientific name of the microbe used for fermenting malted cereals, And fruit juices., ANS---Saccharomyces cerevisiae., Q.3 Consuming curd keeps the gastrointestinal tract intact. Give reason ., ANS---Curd contains lactic acid bacteria which checks the growth of disease –causing, Microbes and protects the gastrointestinal tract., Q.4 Name the group of organisms and the substrate they act on to produce biogas., ANS----Group of organisms – Methanogens, Substrate--- Cellulose material /Cow dung /agriculture waste., Q.5 How is the presence of cyanobacteria in the paddy field beneficial to rice crop?, ANS---Cyanobacteria can fix atmospheric nitrogen in paddy fields .it act as an important biofertiliser., They also add organic matter to soil and increase its fertility., Q.6 What are biofertilisers? Give two examples., ANS----Biofertilisers are organisms that enrich the nutrients in the soil e.g Rhizobium, Azotobacter., Q.7 Different variety of cheese is known by their texture, flavors and taste. A variety of cheese is having “pores” in it. State the reason behind this., Ans. Large amount of CO2 evolving through the production of cheese, Q 8 What would happen if our intestine harbours microbial flora exactly similar to that found in rumen of cattle?, Ans. cellulose digestion will take place at higher rate and its function as roughage may not be available., Q.9 If a given water sample have more BOD, what does it indicate?, ANS- More polluted or more organic material present in it., SHORT ANSWER QUESTIONS(2MARKS), Q.1 Mention a product of human welfare obtained with the help of help of each one of the, Following microbes:, a)LAB b)Saccharomyces cerevisiae c) Propionibacterium sharmanii d)Aspergillus niger, ANS---a)Convert milk to curd b) Bread/ alcoholic drinks, c)Swiss cheese d) Citric acid, Q.2Name the microbes that help producton of the following products commercially:, a)Statin b)Citric acid c) Penicillin d) Butyric acid, ANS---------a)Monascus purpureus b)Aspergillus niger, c)Penicillium notatum d)Clostridium butylicum, Q.3 Name the blank spaces a,b,c and d given in the following table :, ANS----------a)Streptococcus b)Fungus c)Cyclosporin-A d) Clostridium butylicum, Q.4 Name the source of statin and state its action on the human body., ANS---Yeast –Monascus purpureus .It acts a blood-cholesterol lowring agent by competitively, inhibiting the enzy, Q.5 Match the following list of bacteria and their commercially important products:, (i) Aspergillus niger (a) Lactic acid, (ii) Acetobacter aceti (b) Butyric acid, (iii) Clostridium butylicum (c) Acetic acid, (iv) Lactobacillus (d) Citric acid, ANS-. i d, ii c, iii b, iv a, SHORT ANSWER QUESTIONS(3 MARKS), a. Name the gaseous components of bio gas?, b. Which bacterium is responsible to produce this gases?, c. Name the institute which developed the technology of gas production?, ANS- a. methane 60%, CO2 40%, b. methanobacterium, c. IARI and KVIC, Given below is a list of six microorganisms. State their usefulness to humans., Nucleopolyhedrovirus (b) Sacccharomyces serevisiae, Monascus purpureus (d) Trichoderma polysporum, Penicillium notatum (f) Propionibacterium sharmanii, Ans: (a) Nucleopolyhedrovirus : Used as bio-control agents., Sacccharomyces serevisiae : Used in bread making and in brewing industry, Monascus purpureus: Cholesterol lowering agent, Trichoderma polysporum: Produces Syclosporin-A, used as immunosuppressive agent., Penicillium notatum: Produces antibiotic penicillin., Propionibacterium sharmanii: Produces large amount of CO2 in Swiss cheese, LONG ANSWER QUESTION (5 MARKS), “Microbes play a dual role when used for sewage treatment as they not only help to retrieve usable water but also generate fuel”. Explain., Ans:, Microbes naturally present in the sewage are employed in the secondary treatment of the sewage, The effluent from the primary treatment is passed into large aeration tanks., This allows the rapid growth of aerobic microbes into flocs which consume the organic matter of the sewage and reduce the BOD., Then the effluent is passed into a settling tank, where the flocs are allowed to sediment forming the activated sludge, Major parts of this activated sludge is pumped into anaerobic sludge digester, where the anaerobic bacteria digest microbes in the activated sludge., Explain the significant role of the genus Nulephyhedrovirus in an ecological sensitive area, OR, Explain the role of baculovirus as biological control agents. Mention their importance in organic farming., ANS: Baculovirus are pathogens that attack insects and other arthropods. Baculoviruses of genus Nulephyhedrovirus are used as biological control agents. They are excellent candidates for species-specific, narrow spectrum insecticidal applications. They do not show negative impact on plants, mammals, birds, non-target insects. Therefore, they are used as biological control agents., Importance in organic farming: It is desirable when beneficial insects are being conserved to aid in an overall Integrated Pest Management (IPM) programme. In organic farming, it is used to conserve beneficial insects and kills harmful ones., DIAGRAM BASED QUESTION, a) Observing the figure below comment on the relationship between DO and Sewage discharge., b) Give the term for the criteria which decides the level of pollution of water body., Ans. A) As sewage discharged in water body increases, the concentration of DO decreases because of increase in organic content there., b) BOD= Biological Oxygen Demand, This is biogas plant . label D,B and C, Ans. D= methane, B= digester, C= sludge., Chapter-11 Biotechnology: Principles and Processes, MULTIPLE CHOICE QUESTIONS, Bacteria protect themselves from viruses by fragmenting viral DNA with-, Ligase, Endonuclease, Exonuclease, Gyrase, Ans- Endonuclease, RNA interference helps in-, Cell proliferation, Micropropagation, Cell defence, Cell differentiation, Ans- Cell defence, ASSERTION REASONING QUESTIONS, Assertion: The pH of the culture medium changes with the progression of culture ., Reason: So pH control system is employed to maintain constant pH during culture period., A - Both A and R are true and R is the correct explanation of A., B - Both A and R are true but R is NOT the correct explanation of A., C - A is true but R is false., D - A is false but R is true., E - Both A and R are false., Ans- A, Assertion : DNA fragments move towards the anode during the process of gel electrophoresis., Reason : DNA is negatively charged due to presence of phosphate groups., A - Both A and R are true and R is the correct explanation of A., B - Both A and R are true but R is NOT the correct explanation of A., C - A is true but R is false., D - A is false but R is true., E - Both A and R are false., Ans- A, Assertion: BAC and YAC are preferred over plasmids as vectors ., Reason: BAC and YAC are artificially designed vectors., A - Both A and R are true and R is the correct explanation of A., B - Both A and R are true but R is NOT the correct explanation of A., C - A is true but R is false., D - A is false but R is true., E - Both A and R are false., Ans- B, Assertion: To obtain DNA from a plant cell, the enzymes used are chitinase, protease, RNAse., Reason: Chitinase, protease and RNAse will break the cell wall , proteins and RNA extract the DNA., A - Both A and R are true and R is the correct explanation of A., B - Both A and R are true but R is NOT the correct explanation of A., C - A is true but R is false., D - A is false but R is true., E - Both A and R are false., Ans- D, Assertion: Restriction enzymes are used to cut DNA to obtain sticky ends., Reason: DNA ligase can easily form hydrogen bonds between the sticky ends of complementary cut counter parts., A - Both A and R are true and R is the correct explanation of A., B - Both A and R are true but R is NOT the correct explanation of A., C - A is true but R is false., D - A is false but R is true., E - Both A and R are false., Ans- C, CASE BASED QUESTIONS-, Read the given passage and answer any four of the given questions-, Recombinant DNA (rDNA) molecules are  molecules formed by laboratory methods of  (such as ) that bring together genetic material from multiple sources, creating  that would not otherwise be found in the ., Recombinant DNA is the general name for a piece of DNA that has been created by combining at least two fragments from two different sources. Recombinant DNA is possible because DNA molecules from all organisms share the same chemical structure, and differ only in the  sequence within that identical overall structure. Recombinant DNA molecules are sometimes called chimeric DNA, because they can be made of material from two different species, like the mythical . R-DNA technology uses  and leads to the production of ., The DNA sequences used in the construction of recombinant DNA molecules can originate from any . For example, plant DNA may be joined to bacterial DNA, or human DNA may be joined with fungal DNA. In addition, DNA sequences that do not occur anywhere in nature may be created by the , and incorporated into recombinant molecules. Using recombinant DNA technology and synthetic DNA, literally any DNA sequence may be created and introduced into any of a very wide range of living organisms., Name the enzymes which are used for lysis of bacterial, plant, fungal cell., Lysozyme , cellulose, chitinase, Cellulose, protease, lysozyme, Lysozyme, DNAase, cellulose, None of the above, Which chemical is used for precipitation of DNA?, Chilled methanol, Chilled ethanol, Ribonuclease, Protease, Where does EcoR-I cut in the palindromic sequence GAATTC, CTTAAG?, Between A T, Between G A, Between T C, None of the above, Which technique is used for separation of DNA fragments in r-DNA technology?, PCR, Agarose gel electrophoresis, Bioreactors, Down streaming processing, How are sticky ends helpful in forming chimeric DNA?, Sticky ends form hydrogen bonds with the complementary cut counter parts, Stickiness of the ends facilitates the action of DNA ligase., Both the above, None of the above, Ans- 1.1 a) lysozyme, cellulose, chitinase, 1.2 b) chilled ethanol, 1.3 b) Between G A, 1.4 b) Agarose gel electrophoresis, 1.5 c) Both the above, 2. A  is an indispensable part of any  irrespective of whether the process degrades  or produces substances such as foods, feeds, chemicals and pharmaceuticals, and tissues and organs for use in biomedicine. The variety of  is tremendous and many different designs of  have been developed to meet the different needs. In all cases, the bioreactor must provide the environmental conditions necessary for the culture. The specific demands are often conflicting and achieving optimal performance requires attaining the proper balance among the different requirements. Success of a bioprocess depends critically on good design and operation of the bioreactor., 2.1 A simple bioreactor is mainly of two types-, a) Stirred tank bioreactor and sparged tank bioreactor., b) Cell bioreactor and tissue bioreactor, c) Fermentative bioreactor and stirred tank bioreactor, d) Stirred tank bioreactor and cell bioreactor, 2.2 Continuous culture is preferred over batch culture because-, a) batch culture is a closed system that carries out fermentation till nutrients are exhausted whereas continuous culture is an open system, which carries out fermentation for ever., b) batch culture is a open system which continuously carries out fermentation whereas continuous culture is an closed system that carries out fermentation with a fixed amount of nutrients., c) In continuous culture, the culture conditions remain virtually constant (in 'steady state') over extended periods of time. So larger amount of product is formed., d) None of the above, 2.3 To prevent the formation of foam, mechanical foam breakers, ultrasound or, most often, the addition of chemical antifoaming agents are routinely employed in bioreactors and large shake flasks. What are the disadvantages of foam formation during culture in a bioreactor?, a) the effective volume of the liquid increases leading to a loss of culture liquid and microorganisms through air exhaust., b) sterility and containment problems., c) Both the above, d) none of the above, 2.4 What is the function of agitator in a bioreactor?, a) To aerate the mixture well., b) To mix the contents of the bioreactor well., c) To check the growth of microbes in medium., d) All the above., 2.5 The temperature and pH of the culture medium changes with the progression of culture / fermentation. Why?, a) Due to formation of product and metabolism by microbes., b) Due to death of microbes., c) Due to conversion of reactants to products, d) none of the above, ANS- 2.1- a), – c), – c), – b), – a), TOPIC- RESTRICTION ENZYMES, Mention the conventions of naming the restriction endonuclease EcoRI., Ans –The first letter indicates name of genus- Escherichia , and the second two letters are from the name of species- coli from which the enzyme is isolated , the letter R is derived from the name of strain , Roman number indicate the order in which enzyme was isolated (from the strain of bacteria)., Describe the formation of recombinant DNA by the action of EcoRI., Ans – EcoRI identifies its palindromic sequence on both vector DNA and foreign DNA / 5’ GAATTC3’, cuts strands of DNA little away from the centre of palindromic sites , but between same two bases (G and A) , this leaves single stranded portion at the end (sticky ends) on each strand , for recombination both vector DNA and foreign DNA , with similar sticky ends are joined by the enzyme DNA ligase., In 3 mark question diagram is also to be drawn., 3. Explain the significance of ‘palindromic nucleotide sequence’ in the formation of recombinant DNA., Ans - Palindromic nucleotide sequence is the recognition (specific) sequence present both on the vector and on a desired / alien DNA for the action of the same restriction endonuclease to act and cut leading to formation of sticky ends. This helps to form hydrogen bonds between complementary cut counter parts., A recombinant DNA is formed when sticky ends of vector DNA and foreign DNA join. Explain how the sticky ends are formed and get joined., Ans - The vector DNA and foreign DNA are cut by the same restriction enzyme like EcoRI to form the same kind of sticky-ends. Then these sticky ends are joined by the enzyme DNA ligase (with diagram if 3 marks question)., TOPIC- VECTORS, (i) Name the organism in which the vector shown in inserted to get the copies of the desired gene., Mention the area labeled in the vector responsible for controlling the copy number of the inserted gene. What is its other role?, Name and explain the role of a selectable marker in the vector shown., State the role of rop gene., What is pBR322? (5), Ans – (i) Escherichia coli, Origin of replication ‘ori’ controls copy number of inserted gene. It is the site where DNA replication is initiated., The selectable markers are ampR (resistance to ampicillin)and tetR (resistance to tetracycline)., Selectable markers help to select (the host cells which contain the vector) transformants and eliminate the non-transformants., Rop codes for proteins involved in the replication of plasmids., Plasmid /cloning vector of E.coli., Biotechnologists refer to Agrobacterium tumifaciens as a natural genetic engineer of plants. Give reasons to support the statement., Ans – This is because A. tumifaciens can transfer genes naturally by delivering a piece of T- DNA. It has a tumour inducing ( Ti) plasmid., Describe the characteristics that a cloning vector must possess. (3), Ans – (i) A cloning vector must have the following characteristics:, ori or origin of replication, Selectable marker, genes encoding for an antibiotic resistance or genes encoding for α-galactosidase., Cloning site or recognition site for the restriction enzyme to recognize and cut., (a) A recombinant vector with a gene of interest inserted within the gene of, β-galactosidase enzyme, is introduced into a bacterium. Explain the method that would help in selection of recombinant colonies from non-recombinant ones., (b) Why is this method of selection referred to as “insertional inactivation”?, Ans – (a) Bacteria is grown in a medium with chromogenic substrate, blue coloured colonies show non recombinants and colonies with no colour shows recombinants., (b) Gene coding for the enzyme Beta galactosidase is inactivated by insertion og gene of interest., Why is the coding sequence of an enzyme (β-galactosidase) a preferred selectable marker in comparison to antibiotic resistance gene?, Ans –Simpler process , in the presence of a chromogenic substrate ,recombinants are colourless and non recombinants are blue in colour, Name any two natural cloning vectors. Give reasons that make them act as cloning vectors. Write the two characteristics the engineered vectors are made to possess., Ans - Plasmids , bacteriophages, Ability to enter and replicate within bacterial cells, high copy number within the bacterial cells., Characteristics of engineered Vectors: restriction sites of choice,, Selection of recombinants from non- recombinants /selectable marker, AGAROSE GEL ELECTROPHORESIS, (a) Explain the principle on the basis of which DNA is separated by the technique of Gel electrophoresis., (b) How is the separated DNA visualised ?, (c) What is elution ? (3), Ans – (a) Since DNA fragments are negatively charged molecules , they can be seperated by forcing them to move towards the anode, under the electric field through a medium / matrix / Agarose , The DNA fragments seperate as per their size smaller fragments move the farthest., (b) They are visualised by staining with ethidium bromide compound, under exposure of UV light., (c) Removal of DNA bands from agarose gel, and its extraction from gel is elution., Name and describe the technique that helps in separation and isolation of DNA fragments. (3), Ans – Separation and Isolation of DNA Fragments (Gel Electrophoresis),  Firstly, the sample DNA is cut into fragments by restriction endonucleases.,  The DNA fragments being negatively charged to move towards the anode under an electric field through agarose medium/matrix.,  The DNA fragments separate-out according to their size by sieving action on gel.,  The separated DNA fragments are visualised after staining with ethidium bromide followed by exposure to UV radiation.,  The DNA fragments are seen as orange coloured bands.,  The separated bands of DNA are cut out and extracted from the gel piece (elution)., ., Study the diagram given below and answer the questions that follow:, Why have DNA fragments in band ‘D’ moved farther away in comparison to those in band ‘C’?, Identify the anode end in the diagram. (2), Ans – (a) DNA fragments in band ‘D’ are smaller in size than fragments in band ‘C’. Therefore, they moved faster and farther away., The anode end is ‘B’., PCR, (i) Mention the number of primers required in each cycle of polymerase chain reaction (PCR). Write the role of primers and DNA polymerase in PCR., (ii)Give the characteristic feature and source organism of the DNA polymerase used in PCR.(3), ANS- (i) 2, Primers at 5’ end help to initiate the process of DNA replication as DNA polymerase cannot intiate the process of replication. It can only elongate the DNA chain in direction 5’3’., DNA polymerase is thermostable and does not get denatured at high temperature.It is obtained from bacterium Thermus aquaticus., How is the amplification of a gene sample of interest carried out using Polymerase Chain Reaction (PCR)? (3), ANS- 3 STEPS- denaturation, primer annealing, elongation and repeating of cycles in desired number of times with diagram., Name the source organism that possesses Taq polymerase. What is so special about the function of this enzyme? What is the role of heat in PCR? (3), Ans – Thermus aquaticus., Taq polymerase enzyme can tolerate high temperature. It does not get denatured during PCR at high temperature., Heat - Denaturation / separation of DNA into two strands., BIOREACTORS, (a) How has the development of bioreactor helped in biotechnology?, Name the most commonly used bioreactor and describe its working. (3), Ans – (a) Larger biomass / large volume of culture can be processed leading to higher yields of desired specific products (protein / enzymes) , under controlled condition, Stirring type, Mixing of reactor contents evenly (with agitator system or a stirrer), Facilitates oxygen availability, Temperature / pH / foam control // under optimum conditions, How is a continuous culture system maintained in bioreactors and why?(2), Ans – Used medium is drained out from one side of the bioreactor and fresh medium is added from the other side., This type of culturing method produces a larger biomass leading to higher yields (of desired protein) ., Name the type of bioreactor shown. Write the purpose for which it is used. (2), Ans – The given bioreactor is the simple stirred tank bioreactor., Its purpose is large scale production of recombinant protein or enzymes, using microbial plants/animals/human cells., COMPETENT HOST AND OTHER TOPICS, Write any four ways used to introduce a desired DNA segment into a bacterial cell in recombinant technology experiments., Ans – (i) The desired DNA segment is inserted into a cloning vector and the bacterial cell can be made to take it up after making them competent by treating them with specific concentration of divalent cations such as calcium., Microinjection, Biolistics, Disarmed pathogen vector, How does an alien DNA gain entry into a plant cell by ‘biolistics’ method?, Ans - In biolistics method cells are bombarded with high velocity micro-particles of gold or tungsten coated with DNA., Name the host cells in which micro-injection technique is used to introduce an alien DNA., Ans – Animal cells., Why a cell must be made 'competent’ in biotechnology experiments? How does calcium ion help in doing so ?, Ans- To take up the (hydrophilic) DNA from the external medium, - Divalent calcium ions increase the efficiency of DNA entering the cell through pores in the cell wall., 5, CHAPTER-12 BIOTECHNOLOGY AND ITS APPLICATIONS, MIND MAP, MULTIPLE CHOICE QUESTIONS, 1. The process of RNA interference has been used in the development of plants resistant to _____, A. Insects, B. Nematodes, C. Fungi, D. Viruses, Ans- B Nematodes, 2. The first ever human hormone produced by recombinant DNA technology is ___, A. Progesterone, B. Insulin, C. Estrogen, D. Progesterone, Ans- B Insulin, 3. In Bt cotton, the Bt toxin present in plant tissue as pro-toxin in converted into active toxin due to _____, A. Acidic pH of the insect gut, B. Alkaline pH of the insect gut, C. Presence of conversion factors in insect gut, D. Action of gut microorganisms, Ans- B Alkaline pH of insect gut, ASSERTION REASON QUESTIONS-, Assertion: The milk of Rosie cow is nutritionally more balanced for infants., Reason- Rosie’s milk contain 2.4 g/L of human lactalbumin., A - Both A and R are true and R is the correct explanation of A., B - Both A and R are true but R is NOT the correct explanation of A., C - A is true but R is false., D - A is false but R is true., E - Both A and R are false., Ans- A, Assertion: Transgenic animals are used to test the safety of drugs and vaccine before these are administered on humans., Reason: It is easy and quick to test toxicity of drugs and vaccine on transgenic organisms., A - Both A and R are true and R is the correct explanation of A., B - Both A and R are true but R is NOT the correct explanation of A., C - A is true but R is false., D - A is false but R is true., E - Both A and R are false., Ans- C, Assertion: RNAi is a natural method of defence in eukaryotes., Reason: RNAi is used to produce nematode resistant tobacco plants., A - Both A and R are true and R is the correct explanation of A., B - Both A and R are true but R is NOT the correct explanation of A., C - A is true but R is false., D - A is false but R is true., E - Both A and R are false., Ans- A, Assertion: Biopiracy is the practice of commercially exploiting naturally occurring biochemical or genetic material, especially by obtaining patents that restrict its future use, while failing to pay fair compensation to the community from which it originates., Reason: US patented turmeric and neem which is a case of biopiracy., A - Both A and R are true and R is the correct explanation of A., B - Both A and R are true but R is NOT the correct explanation of A., C - A is true but R is false., D - A is false but R is true., E - Both A and R are false., Ans- B, Assertion: Early detection of diseases caused by mutation in genes, HIV and cancer is possible ., Reason: r-DNA technology and its techniques have helped in early molecular diagnosis of genetic diseases, HIV and cancer., A - Both A and R are true and R is the correct explanation of A., B - Both A and R are true but R is NOT the correct explanation of A., C - A is true but R is false., D - A is false but R is true., E - Both A and R are false., Ans- A, CASE BASED QUESTIONS-, Read the passage and answer any 4 questions that follow -, Diabetes is a hyperglycemic metabolic disorder resulting from insufficient production of insulin, with consequent metabolic dysfunctions. Of four types, and affecting more than 415 million people, it is a forefront public health peril globally., Escherichia coli remains the best bacterium prototype for rDNA experiments. Cleavage of the signal polypeptide in Islets of Langerhans produced preproinsulin yields proinsulin, the enzymatic removal of the link chain in which gives Human insulin (humulin); a 51 amino-acids polypeptide of mass 5808Da. In 1978, humulin was first produced in Escherichia coli, eliminating zoonotic cross-transfer/autoimmune-diseases risk. It is also more economical. The manufacturing process can be from separate A and B polypeptide chains, or from proinsulin. An amino acid sequencer manufactures the sequences, which are cloned onto a plasmid. The bacteria are transfected, and placed in fermentation tanks. The insulin molecules are stored in inclusion bodies, and solubilisation (by chemicals and enzymes) and refolding yield the final insulin., How was insulin prepared traditionally ?, From slaughtered hens, From slaughtered pigs, From slaughtered horses, From Slaughtered cattle and pigs, What are the shortcomings of insulin obtained from slaughtered animals?, Insufficient in quantity and contain antibodies which can cause allergy., Insufficient in quantity and contain antigens which can cause allergy., Sufficient in quantity and contain antigens which can cause allergy., None of the above., How did Eli Lily prepared insulin?, By tissue culture technique, By r-DNA technology, By artificial hybridisation, By gene therapy, What is the difference between proinsulin and insulin structurally?, No difference, Proinsulin has an extra C-peptide which is absent in insulin., Insulin has an extra C-peptide which is absent in proinsulin., Proinsulin in inactive form and insulin is active form., How is chain A and chain B of insulin held together?, By hydrogen bonds, By electrostatic bonds, By disulphide bonds, By Vander walls forces, Ans-1.1 d) From slaughtered cattle and pigs, b) Insufficient in quantity and contain antigens which can cause allergy., b) By r-DNA technology, 1.4 b) Proinsulin has an extra C-peptide which is absent in insulin., 1.5 c) By disulphide bonds, 2. Animals with manipulated genetic material (carrying recombinant DNA) are known as transgenic animals. Transgenic technology provides a method to rapidly introduce new genes into animals without cross breeding. It is a powerful technique for studying fundamental problems of mammalian developmen t. Transgenic technology has been developed and found perfect in the laboratory on mice. The three most common gene transfer techniques namely: DNA microinjection, ES-cell mediated and Retrovirus mediated gene transfer are the most important to have enabled to produce transgenic cattle, sheep, goat, pig and other animals. Transgenic animals have the potential of agricultural applications like improved growth rate and carcass composition, improved resistance to disease, increased milk yield, improved wool production and so on. The scientific outlook of right and wrong opinions about transgenic animals is called ethics of transgenic animals. These ethical and animal welfare issues surround transgenic animal technology and be only minimized or avoided through awareness creation about the merit of this technology., 2.1 Which option does not indicate that humans are benefitted from transgenic animals?, a) for study of diseases, b) to determine vaccine safety, c) to test safety of drugs, d) to determine the safety of human alpha lactalbumin, 2.2 Which of the following is a r-DNA vaccine?, a) Cancer, b) cystic fibrosis, c) Hepatitis B, d) Tuberculosis, 2.3 Name the vector which is most commonly used to produce transgenic animals., a) Retrovirus, b) Ti plasmid, c) YAC, d) BAC, 2.4 Transgenic animals are-, a) Those animals whose entire genetic makeup is manipulated., b) Those animals where a foreign gene is not incorporated, c) Mice, d) Those animals in which a foreign gene which is beneficial for mankind is incorporated., 2.5 Name the organization set up by Indian Government to check safety of introducing transgenic animals for human services., a) WHO, b) NBRI, c) CDRI, d) GEAC, Ans- 2.1 d) to determine the safety of human alpha lactalbumin, 2.2 c) Hepatitis B, 2.3 a) Retrovirus, 2.4 d) Those animals in which a foreign gene which is beneficial for mankind is incorporated., 2.5 d) GEAC, BIOTECHNOLOGY- APPLICATIONS IN AGRICULTURE, Name the insect pest that is killed by the products of cryIAc gene. Explain how the gene makes the plant resistant to the insect pest., Ans - Cotton bollworm are killed by products of cry IAc gene., .,  cry gene produces Cry protein in inactive crystalline form. After ingestion by the insect, it becomes active due to the alkaline pH of the gut which solubilise the crystals.,  The activated toxin binds to the surface of midgut epithelial cells thus creating pores which causes cell swelling and lysis , leading to death of the insects., (a)Why do the toxic insecticidal proteins secreted by Bacillus thuringiensis kill the insect and not the bacteria itself?, (b) Name the specific type of gene that is incorporated in a cotton plant to protect the plant against cotton boll worm infestation., Ans – (a) The Bt toxin protein exists as inactive protoxins but once an insect ingests the inactive toxin is converted into an active form due to the alkaline pH of the gut which solubilise the crystals. Therefore, it does not kill the bacteria., (b) cry I Ac / cry II Ab, Explain the process of RNA interference., Ans – RNA interference takes place in all eukaryotic organisms as a method of cellular defence. It involves silencing of a specific mRNA due to a complementary dsRNA molecule that binds to and prevents translation of the mRNA., Name the process involved in the production of nematode-resistant tobacco plants, using genetic engineering. Explain the strategy adopted to develop such plants., Ans – The process involved in the production of nematode-resistant plants is RNA interference or RNAi., Using Agrobacterium vectors, nematode -specific genes were introduced into the host plant. The introduction of DNA was such that it produced both sense and antisense RNA in the host cells. These two RNA’s being complementary to each other are formed, A double stranded RNA (dsRNA) that initiated RNAi and thus, silenced the specific mRNA of the nematode. The consequence was that the parasite could not survive in a transgenic host expressing specific interfering RNA. The transgenic plant thus protected itself from the parasite., Name the vector used for introducing the nematode specific gene in tobacco plant., Ans- Ti plasmid of Agrobacterium tumefaciens, a) List any four beneficial effects of GM plants., Ans – (a) Four beneficial effects of GM plants., Increased tolerance against abiotic stresses (cold, drought, salt, heat)., Reduced reliance on chemical pesticides (pest-resistant crops)., Reduced post-harvest losses., Increased efficiency of minerals used by plants (this prevents early exhaustion of fertility of soil)., Enhanced nutritional value of food, e.g., vitamin ‘A’ enriched rice (golden rice). (Any four), TOPIC – APPLICATIONS IN MEDICAL FIELD, (a) Name the source from which insulin was extracted earlier. Why is this insulin no more in use by diabetic people?, How did Eli Lilly synthesize the human insulin? Mention one difference between this insulin and the one produced by the human pancreas., Ans –(a) Earlier, insulin was extracted from pancreas of slaughtered cattle and pig. This insulin is not in use as some patients developed allergic reaction to this foreign protein, (b) Eli Lilly prepared two DNA sequences corresponding to A and B chains of human insulin and introduced them separately in plasmids of E. coli to produce A and B chains. Chains A and B were produced separately, extracted and combined by creating disulfide bonds to form human insulin., Insulin in human pancreas is synthesized as a pro hormone containing the C peptide which is removed in mature hormone. The r DNA insulin does not contain C peptide and is directly prepared in mature form., (a) Mention the cause and the body system affected by ADA deficiency in humans., Name the vector used for transferring ADA-DNA into the recipient cells in humans. Name the recipient cells., Mention a possible permanent cure for a ADA deficiency patient., Name the deficiency for which first clinical gene therapy was given., What is gene therapy? Name the first clinical case where it was used., Ans – (a) The cause is the deletion of gene responsible for producing ADA. The immune system is affected and one suffers from SCID., (b) A retroviral vector is used, recipient cells are lymphocytes., (c) A possible permanent cure would be gene therapy. In this , c-DNA coding for ADA enzyme is introduced using retroviral vector in lymphocytes of the patient at early embryonic stage., (d) Adenosine deaminase (ADA) deficiency., (e) Gene therapy is a collection of methods that allows correction of a gene defect that has been diagnosed in a child/embryo., Normal functional genes are inserted into an individual’s cells and tissues to treat disease., Why is proinsulin so called? How is insulin different from it?, Ans – Proinsulin is called so because it is an inactive form of insulin ., (a) Suggest any two possible treatments that can be given to a patient exhibiting adenosine deaminase deficiency., (b) Why do children cured by enzyme-replacement therapy for adenosine deaminase deficiency need periodic treatment?, Ans – (a) (i) Enzymes replacement therapy (in which functional ADA is injected), Bone marrow transplantation, Gene therapy / Culturing the lymphocytes followed by introduction of functional ADA cDNA into it & returning it into the patient’s body (Any two), ERT is not a permanent cure so periodic injections of ADA enzyme are required., Two children, A and B aged 4 and 5 years respectively visited a hospital with a similar genetic disorder. The girl A was provided enzyme-replacement therapy and was advised to revisit periodically for further treatment. The girl, B was, however, given a therapy that did not require revisit for further treatment., Name the ailments the two girls were suffering from?, Why did the treatment provided to girl A required repeated visits?, How was the girl B cured permanently?, Ans - (a) Adenosine deaminase (ADA) deficiency, In Enzyme Replacement Therapy) functional ADA is introduced to the patient (by injection), this therapy is not completely curative / enzyme can act only for a limited time period, As there is no permanent cure at the age of five., Insulin in the human body is secreted by pancreas as prohormone/proinsulin. The schematic polypetide structure of proinsulin is given below. This proinsulin needs to undergo processing before it becomes functional in the body. Answer the questions that follow, State the change the proinsulin undegoes at the time of its processing to become functional., Name the technique the American company Eli Lilly used for the commercial production of human insulin., How are the two polypeptides of a functional insulin chemically held together ?, Ans (a) ‘C’ Peptide is removed, r-DNA technology / Recombinant DNA Technology, Disulphide bonds., What are transgenic animals? How was the first transgenic cow found to be more useful than the normal cow, for humans?, Ans. -Animals having undergone DNA manipulation (to express an extra / foreign gene), -(Rosie) produced human protein - enriched milk / 2.4 gm protein per litre which contained human alpha - lactalbumin , and was nutritionally more balanced (product) for human babies than natural cow milk., 14. Expand GEAC. Why has the Indian Government set up the organization named GEAC? Give any two reasons. (3), Ans – GEAC- Genetic Engineering Approval Committee, To check the validity of GM crops, To check safety of introduction of GM organism for public services., Explain the role of transgenic animals in (i) Vaccine safety and (ii) Biological products with the help of an example each. (2), Ans - (i) Vaccine safety- Transgenic mice are developed to test safety of polio vaccine before being used on humans., Human protein (α-1-antitrypsin) is used to treat emphysema., CH 13 : Organisms and Populations, ONE MARK QUESTIONS( VSA TYPE ), Mention how do bears escape from stressful time in winter?, ANS-hibernation, What will the growth rate pattern , when the resources are unlimited?, Ans : Exponential growth, Predators are prudent. Why?, Ans : Because they have to be efficient so that they will get continuous source of prey., How do conformers response to abiotic factors ?, Ans: conformers body environment changes according to the external abiotic factors., Will the distribution level of species be affected by gradual increase in temperature? Say briefly ., Ans: yes ,the pattern of distribution will shift towards the poles with increase temperature., How is orchid ophrys pollinated by sexual deceit?, Ans :One petal of Ophrys bears an uncanny resemblance to the female of the bee in size and colouring. Male bees are attracted and pseudocopulates it resulting in pollination., What is the relationship between egret and grazing cattle? Why?, Ans: Commensalism because egret get benefited and cattle is neither harmed nor benifeted., Why is female mosquito not considered a parasite?, Ans: It does not live in/on the body of the host., What is brood parasitism?, Ans: One species lays eggs in the nest of another bird,lets the host incubatethem.E.g. Cuckoo lays eggs in the nest of a crow, How is liver fluke adapted to parasitism?, Ans: Flat body,suckers for adhering to the host., Gause’s competitive exclusion principle, where does this apply?, Ans:Organisms living closely related and in case if resources are limiting, How is competition avoided in Nature? Give example., Ans: Resource partitioning,two species adopt to have different razing time., How do blubber help the polar seas to adapt in their environment?, Ans: it acts as heat insulator., Biological control methods adopted in agriculture follow concept of which population interaction population ?, Ans :Predation, 15.How the pollinators are rewarded by the plants in return of their pollination ?, Ans: in forms of nectar., B.ASSERTION AND REASON, In the following questions a statement of assertion followed by a statement of reason is given. Choose the correct answer out of the following choices., (a) Assertion and reason both are correct statements and reason is correct explanation for assertion., b) Assertion and reason both are correct statements but reason is not correct explanation for assertion, (c) Assertion is correct statement but reason is wrong statement., d) Assertion is wrong statement but reason is correct statement., 1. Assertion: Species are groups of potentially interbreeding natural populations which are isolated from other such groups., Reason: Distinctive morphological features are displayed due to reproductive isolation., 2. Assertion: Leaf butterfly and stick insect show mimicry to dodge their enemies., Reason : Mimicry is a method to acquire body colour blending with the surroundings., 3. Assertion: Small sized animals are rarely found in polar regions., Reason : Small sized animal have larger surface area relative to their volume and have to spend energy to generate body heat., 4. Assertion: A stable population is depicted by bell-shaped age pyramid., Reason :The proportion of individuals in reproductive age group is higher than those in pre reproductive age group., 5. Assertion :Plant-animal interactions do not generally involve co-evolution of the mutualist organisms., Reason :Evolution of plants and animals go side by side., 6. Assertion: Predators are organisms which feed on other individuals., Reason : Prey species have evolved various defences to lessen the impact of predation., 7. Assertion: Population pyramid (graphically) depicts the rate at which population will grow in future., Reason : A triangular population pyramid depicts population size is stable., 8. Assertion: Epiphytes growing on branches of the tree exhibit commensalism., Reason : In commensalism on organism benefits from the association while the other has no effect., 9. Assertion : Coral reefs are found in regions of West Bengal and Andhra Pradesh., Reason: Coral reef require low fresh water inflow, high salinity and optimal temperature to propagate., 10. Assertion: Verhulst-Pearl Logistic growth curve is sigmoid in nature., Reason : A population growing in habitat with imited resources shows an initial lag phase followed by acceleration and deceleration and finally an asymptote., ANSWERS:, 1.(b) 2. (a) 3.(a) 4.(c) 5.(d), 6.(b) 7.(c) 8.(a) 9.(d) 10.(b), 2 MARKS QUESTIONS (SA TYPE 1), 1. What is mutualism? Mention any two examples where the organisms involved are, commercially exploited in agriculture., Ans. Mutualism is interaction between two organisms of different species which give, benefits to both. Two examples where the organisms involved are commercially exploited in agriculture – i) Rhizobium in root nodules of legume, ii) mycorrhiza is associated between fungi like Glomus and the roots of higher plants., 2. How does our body adapt to low oxygen availability at high altitudes?, Ans. Our body adapts to low oxygen availability by increasing red blood cell production, decreasing the binding capacity of haemoglobin and by increasing breathing rate., 3. ``Snow leopards are not found in Kerala forest and tuna fish are rarely found beyond tropical latitude in the ocean`` . Study the above two case and state the possible reason for the same., Ans. Change in temperature from their established habitats affects the kinetics of the, enzyme and through it, the basal metabolism, activity and other physiological functions of the organisms., 4. What are the limiting factors of population growth?, Ans. Predators, parasites. Diseases, food scarcity, competition, adverse weather are the limiting factors for population growth ., 5. In what respects are the developed nations better than the developing nations?, Ans. Developed nation have higher per capita income, lower rate of population growth and better life facilities than the developing nation., 6. What does J-shaped growth curve of population indicate?, Ans. The J-shaped growth curve indicates the minimum or absence of environmental, resistance., 7. State Gause,s competitive exclusion principle., Ans. Gause,s competitive exclusion principle state that two closely related species, competing for same resources cannot coexist indefinitely, the inferior will be eliminated by the superior one., 8. How does an age pyramid for human population at given point of time helps the policy makers in planning the future., Ans. Age pyramid is graphic structure of different age groups in population at any given with per reproductive group at base, reproductive in middle and post reproductive at the top. Age pyramids show age distribution of males and females in a combined diagram., 9. Why the plants that inhabit a desert are not found in a mangrove? Give reason., Ans. In mangroves the soil is oxygen deficit because of excess water present. Plants in mangroves develop special roots called breathing roots or pneumatophores for respiration.This adaptation is not present in desert plants because of which they cannot survive in mangroves., 10. Distinguish between hibernation and aestivation, 3 MARKS QUESTIONS (SA-II ), 1. Name the type of interaction seen in each of the following examples:, i) Ascaris worms living in the intestine of humans, ii) Wasp pollinating fig inflorescence, iii) Clown fish living among the tentacles of sea-anemone, vi) Mycorrhizae living on the roots of higher plants, v) Orchid growth on the branch of a mango tree, vi) Sucker fish and shark., 2. Apart from being part of food chain, predators play other important roles. Mention any one such roles supported by examples., Ans. Predation acts as channels for energy transfer across trophic levels. They keep prey population under control. Biological control of weeds and pests based on the ability of the predator to regulate prey population e.g prickly pear cactus was brought under control by cactus feeding moth., 3. Co-evolution is a spectacular example of mutualisms between an animal and a plants.Describe co-evolution with the help of an example., Ans. Co-evolution can be observed in fig(plant) and wasp(animals). The female wasp used the fruit for egg laying. It also used developing seeds within the fruit for nourishment its larvae. The wasp in turn pollinates the fig inflorescence. The given fig species can be pollinated by its partner wasp species and no other species., 4. The animals parasites while living in or on their host species have evolved certain, adaptation which enable them to survive and propagate. Highlight these adaptations along with examples., Ans. The special adaptation that have evolved in parasites are, I) The loss of unnecessary sense organs as in case of lice, mites and fleas there is the, absence of wings, ii) The presence of adhesive organs or suckers on to the host like in tapeworms and leeches., iii) The loss of digestive system i.e tapeworms., iv) High reproductive capacity e.g. round worms produces large progeny, 5 . Study the three different age pyramids for human population given below and answer the questions that follows:, Write the names given to each of these age pyramids., Mention the one , which is ideal for human population and why?, ANS- i) A- Expanding B) Stable C) – Declining, ii.Stable population is ideal for human population.It represents sustainable livivg., D: CASE BASED QUESTIONS, Read the following and answer any four question given below, A group of organisms living in the same area at the same time and can interbreed is called a population. Main attribution of the population are as follows, Density, D=N/S Birth rate(Natality)- production of new individuals in a population over fixed time period. Death rate or Mortality- Number of individual dying in a population over fixed time period is called death rate. Sex ratio – The number of male or female per 1000 individuals in a given time is called as sex ratio., i)World population double in, (a) 15years, (b) 20 years, (c) 30 years, (d) 35 years, Ans (d), ii) Population increases by, (a)Natality, (b) immigration, (c) mortality, (d) emigration, Ans. a) and b) both, iii) Natural capacity of a population to grow at its maximum rate is called, (a) natality, (b) Biotic potential, (c) Amniocentesis, (d) carrying capacity, Ans (b), iv) Population explosion occurred inthe last, (a)500 years, (b) 300 years, (c) 100 years, (d) 50 years, Ans (c), v) Assertion- Over population has become a serious problem in the developing countries., Reason-It may be exhaust natural resources cause unemployment and lead the pollution ., (a)Both assertion and reason are true, and the reason is correct explanation of the assertion, (b) Both assertion and reason are true, but the reason is not the correct explanation of assertion, (c) Assertion is true but reason is false, (d) Both assertion and reason are false, ANS-(a), 2.Read the following and answer any four question given below, Interspecific interaction are the interactions of population of two different species. They could be beneficial, detrimental or neutral to one of the species or both. Both the species benefit in mutualism and both lose in competition. In parasitism and predation, only one species benefits and the interaction is harmful to the other species., i) Amensalism is an association between two species where, (a) one species is harmed and other is benefitted, (b) one species is harmed and other is unaffected, (c) one species is benefitted and other is unaffected, (d) both the species are harmed, Ans. (c), ii) lichens are the association of, (a) bacteria and fungus, (b) algae and bacteria, (c) fungus and algae, (d) fungus and virus, Ans (c), iii) Which of the following is a partial root parasite?, (a)Sandal wood, (b)Mistletoe, (c)Orobanche, (d)Gandoderma, Ans (a), iv)Parasite can be explained as an organism which depends on other, (a)For food, (b)For shelter, (c) For both food and shelter, (d) for reproduction, Ans (c), v)Assertion- pathogenic bacteria do not multiply well in the soil, Reason- antibiotic producing fungi and bacteria are common in soil, (a)Both assertion and reason are true , and the reason is correct explanation of the assertion, (b) Both assertion and reason are true, but the reason is not the correct explanation of assertion, (c) Assertion is true but reason is false, (d) Both assertion and reason are false, Ans (a), E.5 MARKS QUESTIONS(LA TYPE), 1., B, Chapter 15 – Biodiversity and its conservation, ONE MARK QUESTION, India has more than 50,000 strains of rice. Mention the level of biodiversity it represents., Ans – 50,000 strains of rice represent specific biodiversity., Write the importance of cryopreservation in conservation of biodiversity., Ans – By cryopreservation, the reproductive parts of rare species can be preserved., Name the type of biodiversity represented by the following:, 50,000 different strains of rice in India, Estuaries and alpine meadows in India. Ans - (i) Genetic diversity (ii) Ecological diversity, Name the type of biodiversity represented by the following:, 1000 varieties of mangoes in India., Variations in terms of potency and concentration of reserpine in Rauwolfia vomitoria growing in different regions of Himalayas., Ans – (i) Genetic diversity, Genetic diversity, List any four techniques where the principle of ex-situ conservation of biodiversity has been employed., Ans - Cryopreservation , in vitro fertilisation, micro propagation / tissue culture , sperm bank/ seed bank / gene bank, What is biopiracy?, Ans – Biopiracy is the use of bioresources by multinational companies and other organization without proper authorization/compensation payment to the concern country /organisation., Why are sacred grooves highly protected?, Ans – Sacred groves are highly protected - because of religious and cultural traditions, refuges for large number of rare and threatened plants / ecologically unique and biodiversity rich regions, One of the ex situ conservation methods for endangered species is, (A) Biosphere reserves (B) National parks, (C) Cryopreservation (D) Wildlife sanctuaries, Ans – (C) Cryopreservation, Identify ‘a’ and ‘b’ in the figure given below representing proportionate number of major vertebrate taxa., Ans – (a) Mammals, (b) Amphibians, TWO MARKS QUESTION, In the biosphere immense biological diversity exists at all levels of biological organisation. Explain any two levels of biodiversity., Ans – Two levels of biodiversity are:, Species diversity: It is the diversity at species level. Eg., amphibian species are found more in the Western Ghats as compared to the Eastern Ghats., Genetic diversity: A single species shows high diversity at the genetic level over its distributional range. Eg., Different genetic varieties of Rauwolfia vomitoria are found on the Himalayas., Why certain regions have been declared as biodiversity “hot spots” by environmentalists of the world? Name any two “hot spot” regions of India., Ans - Certain regions have been declared as “hot spots” for maximum protection of these regions which have high levels of species richness and high degree of endemism., Western Ghats and Himalayas are two example of hot-spots., Giving two reasons explain why there is more species biodiversity in tropical latitudes than in temperate ones., Ans – The reasons are:, Tropical environments unlike temperate ones, are less seasonal, relatively more constant and predictable which promote greater species diversity., There is more solar energy available in the tropics which contribute to higher productivity leading to greater diversity., Alien species are a threat to native species. Justify taking examples of an animal and a plant alien species., Ans – Fungi: They form thick-walled spores which help them survive in unfavourable conditions. On availability of suitable environment, these germinate., Zooplankton: Under unfavourable conditions, these species in lakes and ponds enter diapause, a stage of suspended development., Bears: In extreme low temperatures, they escape winter time, i.e., they hibernate., Justify with the help of an example where a deliberate attempt by humans has led to the extinction of a particular species., Ans – When Nile perch, a large predator fish, was introduced in Lake Victoria, it started feeding on the native fish, chichlid fish. As a result, chichlid fish became extinct and Nile perch, not finding any food for itself, died too., The above graph shows species–area relationship. Write the equation of the curve ‘a’ and explain., Ans – The equation of the curve ‘a’ is S = CAZ., Within a region, species richness increases with increasing explored area but only up to a limit., Relationship between species richness and area for a wide variety of taxa turns out to be rectangular hyperbola, Differentiate between in situ and ex situ approaches of conservation of biodiversity., Ans –, Where would you expect more species biodiversity— in tropics or in polar regions? Give reasons in support of your answer., Ans – More biodiversity is found in the tropics. This is because tropical regions remain undisturbed from frequent glaciations as in polar regions. Also, the tropics are less seasonal/more constant., What is meant by “alien species” invasion? Name one plant and one animal alien species that are a threat to our Indian native species., Ans – Some alien or exotic species when introduced unintentionally or deliberately, become invasive and cause harmful impact resulting in extinction of the indigenous species., Why are certain regions on the Earth called hot-spots? Name any two hot-spots in India?, Ans – Certain regions have been declared as “hot spots” for maximum protection of these regions which have high levels of species richness and high degree of endemism. Western Ghats and Sri Lanka and Himalayas are two example of hot-spots., Why should biodiversity be conserved? List any two ethical arguments in its support., Ans – (i) Narrowly utilitarian arguments, Broadly utilitarian arguments, Ethical reasons (Any two), What is Bio piracy? State the initiative taken by the Indian Parliament towards it., Ans – (i) Biopiracy is the use of bioresources by organisations without proper authorisation from the countries and people concerned without compensatory payment., (ii) The government has cleared patent terms, emergency provisions and research and development initiative., Suggest two practices giving one example of each, that help protect rare or threatened species., Ans – (1) In situ conservation , biodiversity hotspot / biosphere reserve / national parks, /sanctuaries / Ramsar sites / sacred groves (Any one), (2) Ex situ conservation , Zoological parks / botanical garden / wild life safari parks / cryopreservation techniques / Tissue culture / seed bank / pollen banks (Any one), State ‘two’ observations made by German naturalist, Alexender von Humboldt during his extensive explorations in South American jungles., Ans – Within a region species richness increases with increasing explored area but only upto a limit, this relation for a wide variety of taxa turns out to be a rectangular hyperbola., THREE MARK QUESTION, Explain, giving one example, how co-extinction is one of the causes of loss of biodiversity. List the three other causes also (without description)., Ans – When a species becomes extinct, the plant and animal species associated with it in an obligatory may also become extinct. This is called co-extinction. For example, when a host fish species becomes extinct, its unique assemblage of parasites also becomes extinct. The three other causes are:, Habitat loss and fragmentation, Over-exploitation, Alien species invasion., Explain ‘rivet popper’ hypothesis. Name the ecologist who proposed it., Ans – Paul Ehrlich proposed the rivet popper hypothesis. This hypothesis states that in an airplane (ecosystem) all parts are joined together using thousands of rivet (species). If every passenger travelling in it starts popping a rivet to take home (causing a species, to become extinct), it may not affect flight safety (proper functioning of the ecosystem) initially but as more and more rivets are removed, the plane becomes dangerously weak over a period of time., (a) What are the two types of desirable approaches to conserve biodiversity? Explain with examples bringing out the difference between the two types., (b) What is the association between the bumble bee and its favourite orchid Ophrys? How would extinction or change of one would affect the other?, Ans – (a) The two types of desirable approaches are: In situ conservation (On site conservation) and Ex situ conservation (Off-site conservation)., (b) Commensalism., If the female bee’s colour patterns change even slightly due to any reason during evolution, pollination success will be reduced unless the orchid flower co-evolves to maintain the resemblance of its petal to the female bee., Alien species are highly invasive and are a threat to indigenous species. Substantiate this statement with any three examples., Ans – (i) Nile perch introduced into lake Victoria in East Africa led to the extinction of Cichild fish., Parthenium/Lantana/Eichhornia are invasive plants and pose a threat to indigenous species., Introduction of African catfish (Clarias gariepinus) to aquaculture is a threat to Indian catfishes., List the reasons that account for greater biological diversity in the tropics., Ans – The three hypotheses to explain species richness in tropics are:, The constant environment in tropics promotes niche specialisation and increased, species diversity., There is longer exposure to solar radiation in the tropical regions that contributes directly to higher productivity and indirectly to greater species diversity., There occurred no glaciation in tropical region and it remained undisturbed. Thus organisms living in tropics continued to flourish and evolved more species diversity., There are many animals that have become extinct in the wild but continue to be maintained in Zoological parks., What type of biodiversity conservation is observed in this case?, Explain any two other ways which help in this type of conservation., Ans – (i) Ex-situ conservation, (a) In-vitro fertilisation: Gametes of threatened species can be fertilised for their propagation., (b) Cryopreservation techniques: Gametes of threatened species can be preserved in viable and fertile condition for long periods., Explain, giving three reasons, why tropics show greatest levels of species diversity., Ans – (i) Tropical latitude have remained relatively undisturbed and have had a long evolutionary time for species diversification., Tropical environments have are less seasonal variations, more constant and predictable environmental conditions. This promotes niche specialisation for greater species diversity., There is more availability of solar energy which contributes to higher productivity., List six advantages of “ex-situ” approach to conservation of biodiversity., Ans – An endangered / threatened species can be conserved / genetic strains of commercially Important plants can be preserved for a long time (seed banks) / biodiversity loss is reduced / gametes of threatened species can be preserved in a viable and fertile condition for long periods (using cryopreservation) / eggs can be fertilized in -vitro / plants can be propagated using tissue culture / economically beneficial / conserve large number of species / aesthetic value = (Any six points), Analyse the effects of ‘Alien species invasion’ on the biodiversity of a given area. Provide two examples., Ans – Introduction of alien species causes decline or extinction of indigenous species due to tough competition for utilization of resources, Examples - Introduction of Nile perch in lake Victoria led to extinction of more than 200 species of Cichlid fish / Introduction of African cat fish (Clarias gariepinus) for aquaculture poses threat to indigenous catfish/ Threat posed to native species by invasive exotic weeds like carrot grass (Parthenium) / Lantana and water hyacinth (Eichhornia) /Extinction of Abingdon tortoise by introduction of goat. (any two), FIVE MARK QUESTION, The following graph shows the species–area relationship. Answer the following questions as directed., Name the naturalist who studied the kind of relationship shown in the graph. Write the observations made by him., Write the situations as discovered by the ecologists when the value of ‘Z’ (slope of the line) lies between, (i) 0.1 and 0.2, 0.6 and 1.2, What does ‘Z’ stand for?, When would the slope of the line ‘b’ become steeper?, Ans – (a) Alexander Von Humboldt., He observed that within a region, species richness increased with increasing explored area but only up to a limit., (i) The slopes regression lines are similar when unaffected distribution in an area is analysed., (ii) The slope of regression is steeper when we analyse the species area relationship among very large areas like entire continent., Z (slope of the line) is the regression co-efficient., If species richness is more i.e. in the range 0.62-1.2., (a) Why is there a need to conserve biodiversity?, Name and explain any two ways that are responsible for the loss of biodiversity., Ans – (a) There are three main reasons for conserving the biodiversity which have been classified into the following categories:, Narrowly utilitarian arguments, Human beings derive direct economic benefits from nature, like food, firewood, fibre, construction material, industrial products (resins, gums, dyes, tannins, etc.) and medicinally important products., More than 25 per cent of the drugs are derived from plants and about 25,000 species of plants are used by native people as traditional medicines., Broadly utilitarian arguments, Biodiversity plays a major role in maintaining and sustaining supply of goods and services from various species as well as ecological systems., The different ecological services provided are:, Amazon forest is estimated to contribute 20 per cent of the total oxygen in the atmosphere on earth., Ecosystem provides pollinators like bees, bumble bees, birds and bats which pollinate plants to form fruits and seeds., Aesthetic pleasures like bird watching, spring flowers in full bloom, walking through the thick forest, waking up to a bulbul’s song, etc. are some other benefits of the ecosystem., Ethical reasons, There are thousands of plants, animals and microbes on this earth which are not useless. Every one has some intrinsic value even if it is not of any economic value to us., It is, therefore, our moral duty to ensure well-being of all the living creatures for the utilisation of future generations., (b) There are four major causes of biodiversity loss. These are also known as ‘The Evil Quartet’. (write any two), Habitat loss and fragmentation, Destruction of habitat is the primary cause of extinction of species., The tropical rainforests initially covered 14 per cent of the land surface of earth, but now cover only 6 per cent of land area., The Amazon rainforest (called the “lungs of the planet”) is being cut and cleared for cultivation of soya beans and for conversion into grasslands for raising beef cattle. When large-sized habitats are broken or fragmented due to human settlements, building of roads, digging of canals, etc., the population of animals requiring, large territories and some animals with migratory habitats declines., Over-exploitation, When biological system is over-exploited by man for the natural resources, it results in degradation and extinction of the resources., For example, Stellar’s sea cow, passenger pigeon and many marine fishes., Alien (exotic) species invasions, Some alien (exotic) species when introduced unintentionally or deliberately, become invasive and cause harmful impact, resulting in extinction of the indigenous species., Nile perch, a large predator fish when introduced in Lake Victoria (East Africa) caused the extinction of an ecologically unique species of Cichlid fish in the lake., Invasive weed species like Parthenium (carrot grass), Lantana and Eicchornia (water hyacinth) caused environmental damage and posed threat to our native species., Introduction of African catfish (Clarias gariepinus) for aquaculture purposes is posing a threat to the indigenous cat fishes of Indian rivers., Co-extinctions, When a species becomes extinct, the plant and animal species associated with it in an obligatory manner, also become extinct., For example, if the host fish species becomes extinct, all those parasites exclusively dependent on it, will also become extinct; in plant–pollinator mutualism also, extinction of one results in the extinction of the other., (a) ‘‘India has greater ecosystem diversity than Norway.’’ Do you agree with the statement ? Give reasons in support of your answer., (b) Write the difference between genetic biodiversity and species biodiversity that exists at all the levels of biological organisation., Ans – (a) Yes, (b) Genetic diversity - Diversity / variation within a species over its distributional range / same explained with the help of a correct example, Species diversity - Diversity / variation at a species level / same explained with the help of a correct example, Alien species invasion has been a threat to biodiversity. Justify with the help of a suitable example. List any other three causes responsible for such a loss., Ans – Example of Alien species invasion, Nile Perch , introduced into lake Victoria ( in East Africa) , led to extinction of Cichlid Fish (more than 200 species) in the lake // Introduction of African cat fish (Clarias gariepinus) , for aquaculture, posing threat to indigenous catfish // Introduction of carrot grass (Parthenium) / Lantana / Water hyacinth (Eicchornia) ,which are invasive weed , that pose threat to native species or any other appropriate example., Causes of biodiversity loss, Habitat loss and fragmentation, Over exploitation, Co-extinction, (a) According to ecologists, tropical regions in the world account for greater biological diversity. Justify., (b) Why are habitat loss and alien species invasion considered as the causes of biodiversity loss ? Explain with the help of an example of each., Ans – (a) (i) have remained relatively undisturbed for millions of years / had a long evolutionary time for species diversification, environment less seasonal / more constant and predictable / such constant environment promotes niche specialization, more solar energy available in the tropics contributes to higher productivity and greater diversity, (b) Habitat loss, Amazon rain forest is being cut for cultivating soyabeans / degradation of habitat by pollution / human activities leading to clearing of forests for commercial or tourism purpose (any other relevant example), Alien species invasion -, The Nile perch introduced into Lake Victoria in East Africa led eventually to the extinction of an ecologically unique assemblage of more than 200 species of cichlid fish in the lake / Recent illegal introduction of the African catfish Clarias gariepinus for aquaculture purposes is posing a threat to the indigenous catfishes in our rivers / carrot grass / lantana / water hyacinth causes threat to our indigenous species, (any other relevant example), ASSERTION & REASON QUESTION :, Mark the correct choice, If both assertion and reason are true and reason is the correct explanation of assertion., If both assertion and reason are true but reason is not the correct explanation of assertion., If assertion is true but reason is false., If both assertion and reason are false., Assertion: Genetic variation shown by the plant Rauwolfia vomitoria growing in different Himalaya range is very important economically., Reason: The amount and variety of alkaloids present in this plant, change both between the Rauwolfia spacies and between the different strains of R vomitoria, Assertion: The Species diversity present in a given community or habitat is referred to as Alpha diversity, Reason: Alpha diversity is usually expressed by species richness and species evenness in that community or habitat, Assertion: If the Species area relationship are analysed among very large area like the entire continent the value of z, is that slope of the line in the range of 0.1 to 0.2, Reason: The value of z is the slope of line of a species area relationship lies in the range of 0.6 to 1.2 when analysis is done among small area, Assertion: Species with low genetic variability are generally at greater risk of extinction then the species with more genetic variability, Reason: Species with low genetic variability are more vulnerable to the disease predators or other environmental challenges, Assertion: Biodiversity hotspots are the regions which possess high level of species richness, high degree of endemism and no loss of habitat, Reason: Total number of biodiversity hotspot in world is 32 with the two of these hotspot found in India, Assertion: Over exploitation of a species reduces the size of its population eventually leading to its extinction, Reason: Steller’s sea cow is a large, herbivorous, terrestrial mammal which is on the verge of extinction due to over exploitation, Assertion: Offsite collections can be used to restock depleted populations, reintroduce species in the wild and restore degraded habitat, Reason: In situ conservation refers to the conservation of endangered species in their natural habitat, Answer : a) – A, b) – A, c) – D, d) – A, e) - D, f) - C, g) - B, CASE STUDY QUESTION:, Loss of biodiversity: Human activities cause loss to biodiversity at very faster rate. According to IUCN Red list (2004), 338 vertebrates, 359 invertebrates and 87 plants (total 784 species) became extinct in last 500 years. Dodo from Mauritius, Quagga from Africa, Thylacine from Australia, Steller's sea cow from Russia and 3 subspecies of tiger namely Javan, Bali and Caspian got extinct in recent years. 27 species became extinct in last 20 years. Amphibian are more vulnerable to extinction. 15500 species  are facing threat of extinction which includes 32% of Ambhibian species, 12% of bird species, 23% of mammalian species and 31 % of gymnosperm., Loss of biodiversity in a region may lead to decline in plant production. Lower resistance to environmental perturbation (deviation from the normal state) like droughts or floods. Change in plant productivity, water use, pest and disease cycle., i) How much area of earth are covered by tropical for currently, a) 5%, b) 8%, c) 6%, d) 10%, ii) Nile perch in Victoria lake of South Africa caused extinction of, a) Catfish fish, b) cichlid fish, c) rohu fish, d) all of these, iii) Scientific name of African catfish is responsible for the extinction of catfish in India rivers is, a) Clarias gariepinus, b) Berrylius vagra, c) Gagata Xenia, d) Rita chrysea, iv) Which of the following is most important reason of biodiversity loss, a) Frugmentation and habitat loss, b) Alien special invasion, c) Over exploitation, d) Coextinction, v) Region of biosphere reserve which is legally protected and prohibited for human activities is called, a) Restoration zone, b) Core zone, c) Transition zone, d) Buffer zone, Part 2, Sample Paper, Sample Paper 1, BLUE PRINT BIOLOGY – MODEL PAPER, BIOLOGY, SAMPLE PAPER-1, Class XII Biology (044) Theory, Time3 hours Maximum Marks: 70, General Instructions:, (i) All questions are compulsory., (ii) The question paper has four sections: Section A, Section B, Section C and Section D.There are 33 questions in the question paper., (iii) Section–A has 14 questions of 1 mark each and 02 case-based questions. Section–B has 9 questions of 2 marks each. Section–C has 5 questions of 3 marks each and Section–D has 3 questions of 5 marks each., (iv)There is no overall choice. However, internal choices have been provided in some questions. A student has to attempt only one of the alternatives in such questions., (v) Wherever necessary, neat and properly labeled diagrams should be drawn., Section A, Name the ‘a’ and ‘b’ of the given pie chart representing the biodiversity of plant showing their proportionate number of species of major taxa., What is meant by trisomic condition?, What are cytokine barriers?, Mention two adaptations found in Kangaroo rat to survive in desert conditions, Name the source of smack. Mention one way in which it affects the human body., In the absence of the predators, which curve, (a) or (b) would approximately depict the prey population?, State the role of transposons in silencing of mRNA in eukaryotic cells., How many chromosomes do drones of honey bee possess? Name the type of cell division involved in the production of sperm in them., How do histones acquire positive charge?, What is Biopiracy?, Assertion: An organism with a lethal mutation may not even develop beyond the zygote stage., Reason: All types of gene mutations are lethal., Both assertion and reason are true and reason in the correct explanation of assertion., Both assertion and reason are true but reason is not the correct explanation of assertion., Assertion in correct but the reason is incorrect., Assertion is incorrect but the reason is correct., Assertion: National parks and Wild life sanctuaries are meant to conserve the organisms in their natural habitat., Reason: Both are the good examples of in-situ conservation, Both assertion and reason are true and reason in the correct explanation of assertion., Both assertion and reason are true but reason is not the correct explanation of assertion., Assertion in correct but the reason is incorrect., Assertion is incorrect but the reason is correct., Assertion: Diapause and aestivation are the ways to suspend the activities during unfavourable environmental conditions., Reason: These mechanism help regulators to live successfully in changing environmental conditions., Both assertion and reason are true and reason in the correct explanation of assertion., Both assertion and reason are true but reason is not the correct explanation of assertion., Assertion in correct but the reason is incorrect., Assertion is incorrect but the reason is correct., Assertion: Cell mediated immune response is responsible for graft rejection., Reason: B Lymphocytes produces humoral response through antibody production., Both assertion and reason are true and reason in the correct explanation of assertion., Both assertion and reason are true but reason is not the correct explanation of assertion., Assertion in correct but the reason is incorrect., Assertion is incorrect but the reason is correct., We use microbes or products which are derived from them, every day. A common example is the production of curd from milk. Micro-organisms such as Lactobacillus and others commonly called lactic acid bacteria (LAB) grow in milk and convert it to curd. The dough, which is used for making foods such as Dosa and Idli is also fermented by bacteria. A number of traditional drinks and foods are also made by fermentation by the microbes. ‘Toddy’, a traditional drink from some parts of southern India is made by fermenting sap from palms. The ‘Roquefort cheese’ is ripened by growing specific fungi on them, which gives them a particular flavour. Different varieties of cheese are known by their characteristic texture, flavour and taste, the specificity coming from the microbes used., Which of the following organisms is used in the production of beverages?, Penicillium notatum, Saccharomyces cerevisiae, Aspergillus niger, Clostridium butylicum, Microbes are present in, Soil, Milk, Polluted water, Everywhere, The curd is more nutritionally balanced than milk due to the presence of, More protein, More calcium, Vitamin B12, Vitamin C, The large holes seen in ‘Swiss Cheese’ are due to, Production of large amount of CO2, Production of O2, Due to the presence of water, Due to the production of lactic acid, OR, Which of the following is produces after distillation, Beer, Whisky, Brandy, Both b and c, After implantation, finger like projections appear on the trophoblast called chorionic villi which are surrounded by the uterine tissue and maternal blood. The chorionic villi and uterine tissue become integrated with each other and jointly form a structural and functional unit between the developing embryo and maternal body. Placenta also acts as an endocrine tissue and produces several hormones. At pregnancy, the levels of other hormones like estrogens, progesterone, cortisol, prolactin are increased several folds in the maternal blood. Increased production of these hormones is essential for supporting the foetal growth, metabolic changes in the mother. The average duration of human pregnancy is about 9 months which is called the gestation period. Parturition is the delivery of the foetus. Parturition is induced by a complex neuroendocrine mechanism., Which of the following hormones is not secreted by the placenta?, hCG, Estrogens, Progesterone, LH, The placenta facilitates, The supply of oxygen, Supply of nutrients to the embryo, Removal of CO2 and waste material produced by the embryo, All of these, The signal of Parturition originates from, Fully developed foetus, The placenta, Both (a) and (b), None of these, In adult Human females oxytocin, Stimulates the pituitary to secrete vasopressin, Cause strong uterine contractions during parturition, Stimulates the growth of mammary gland, It is secreted by the anterior pituitary., OR, Which of the following hormone is secreted in later stages of pregnancy by the ovary?, Progesterone, Luteinizing Hormone, Relaxin, hPL, Section B, Suggest a method to an infertile couple where both are unable to produce gametes., Explain, taking one example, the effect of coextinction in biodiversity., How is ‘Rosie considered different from a normal cow? Explain., Or, Write the functions of, Cry IIab gene, GEAC, Name the category of codon UGA belongs to. Mention another codon of the same category. Explain their role in protein synthesis., List the attributes that populations but not the individual possess., Explain the significant role of the genus Nucleopolyhedrovirus in an ecological sensitive area., In snapdragon, a cross between true breeding red flower (RR) plants and true breeding white flowered (rr) plants showed progeny of plants with all pink flowers., The appearance of pink flower is not known as blending. Why?, What is this phenomenon known as?, Rohit develops symptoms like watery eyes, sneezing and running nose on coming in contact with dust during cleaning his room., Name the type of antibody and chemicals responsible for such a response?, Mention the name of a drug that could be taken by him to get the relief., Differentiate between ZZ and XY type of sex determination mechanism, Section C, Draw a diagram of the transverse section of a bilobed anther. Label any six parts of it., Or, Draw the following diagram related to human reproduction and label them:, The zygote after the first cleavage., Morula stage., Blastocyst stage, Explain the process of transcription in prokaryotes. How is the process different in eukaryotes?, Mention the name of the causal organism, symptoms and the mode of transmission of the disease amoebiasis., Or, Explain the term primary lymphoid organ and secondary lymphoid organs with suitable examples., Describe any three potential applications of genetically modified plants., Or, Describe briefly the following:, Origin of replication, Bioreactors, Downstream processing, Ans, The following graph shows the species-area relationship. Answer the following questions as directed:, Name the naturalist who studied the kind of relationship shown in the graph. Write the observations made by him., Write the situations as discovered by the ecologists when the value of Z lies between:, 0.1 and 0.2, 0.6 and 1.6, When would be the slope of the line ‘b’ become steeper?, Section D, i. Draw the embryo sac of the flowering plant and label central cell, chalazal end of the embryo sac and synergids., ii. Name the cell that develops into the embryo sac and explain how this cell leads to the formation of embryo sac. Also mention the role played by the various cells of the embryo sac., Or, Describe the events of spermatogenesis with the help of schematic representation., Write two differences between spermatogenesis and oogenesis., i. How are Mendelian inheritance, polygenic inheritance and pleiotropy different from each other?, ii. About 8% of human male population suffers from colour blindness, whereas only about 0.4% of human female population suffers from this disease. Write an explanation to show how it is possible?, Or, Describe the Hershey and Chase experiment. Write the conclusion drawn by them., EcoRI is used to cut a segment of foreign DNA and that of a Vector to form a recombinant DNA., To which class EcoR1 belong? Why?, What are Palindromes? Write the palindromic sequence for EcoR1., With the help of schematic diagram show the sticky ends formed on both the segments where the two DNA segments will join later to form a recombinant DNA., OR, Explain the steps involved in the production of genetically engineered insulin. Why is insulin thus produced preferred to the one produced from non-human sources?, ANSWER KEY-1, SAMPLE PAPER -2, Class XII Biology (044) Theory, Time3 hours Maximum Marks: 70, General Instructions:, (i) All questions are compulsory., (ii) The question paper has four sections: Section A, Section B, Section C and Section D.There are 33 questions in the question paper., (iii) Section–A has 14 questions of 1 mark each and 02 case-based questions. Section–B has 9 questions of 2 marks each. Section–C has 5 questions of 3 marks each and Section–D has 3 questions of 5 marks each., (iv)There is no overall choice. However, internal choices have been provided in some questions. A student has to attempt only one of the alternatives in such questions., (v) Wherever necessary, neat and properly labeled diagrams should be drawn., SECTION-A, Why does failure of testes to descend into the scrotum lead to male sterility? 1, Protein crystals containing toxic proteins do not kill Bacillus bacteria. Why? 1, Name the type of pollination that brings genetically different pollen to stigma of a plant. 1, Which strand of transcription unit is transcribed to RNA? 1, Why does DNA move towards the anode in gel electrophoresis? 1, dN /dt = rN(K-N/K). Explain ‘K’ in the given equation. 1, Give any two examples of diseases caused due to trisomy condition. 1, Name the important component of mammary gland secretion that helps in developing resistance in the new born baby? 1, A colour blind man transfers this trait to his daughter only and never to his son. Why? 1, Name the hormone which is only produced from placenta? 1, Assertion: In a monohybrid cross, F1 generation indicate dominant 1 characters., Reason: Dominance occurs only in heterozygous state., Both the assertion and the reason are true and the reason is a correct explanation of the assertion., Both the assertion and reason are true but the reason is not a correct explanation of the assertion., Assertion is true but the reason is false., Both the assertion and reason are false., OR, Assertion: An organism with lethal mutation may not even develop beyond the, zygote stage., Reason: All types of gene mutations are lethal., a. Both assertion and reason are true, and the reason is the correct, explanation of the assertion., b. Both assertion and reason are true, but the reason is not the correct, explanation of the assertion., c. Assertion is true but reason is false., d. Both assertion and reason are false, Assertion: Species richness contributes to the well being of the 1, ecosystem., Reason: Rich biodiversity contributes to higher productivity of the, ecosystem., Both the assertion and the reason are true and the reason is a correct explanation of the assertion., Both the assertion and reason are false., Both the assertion and reason are true but the reason is not a correct explanation of the assertion., Assertion is true but the reason is false., Assertion: Downstream processing is employed to obtain and purify the biological product after mass production., Reason: Biological product needs different type of processing depending on its usage., Both the assertion and the reason are true and the reason is a correct explanation of the assertion., Both the assertion and reason are true but the reason is not a correct explanation of the assertion., Assertion is true but the reason is false., Both the assertion and reason are false., Assertion: An overwhelming majority of animals and nearly all plants can 1, not maintain constant internal environment., Reason: These plants and animals are simply conformers., Both the assertion and the reason are true and the reason is a correct explanation of the assertion., Both the assertion and reason are true but the reason is not a correct explanation of the assertion., Assertion is true but the reason is false., Both the assertion and reason are false., Read the following and answer any four questions from 15(i) to 15(v) given below: 4, BIOFUEL, The biogas plant consists of concrete tank in which bio wastes are collected, and slurry of dung is fed. Biogas typically refers to a gas produced by the, biological breakdown of organic matter in the absence of oxygen. Organic, waste such as dead plant and animal material, animal dung, and kitchen waste, can be converted into a gaseous fuel called biogas. Biogas originates from, biogenic material, for example through anaerobic digestion, and is a type of, biofuel. This fuel is used for cooking ,lightening etc., 15 (i) The technology of biogas production was developed by:, Indian Agricultural Research Institute and Khadi and village industries commission., Indian Astronomical Research Institute and Khadi and village industries committee., Indian Agricultural Research Institute and Khadi and village institutes commission, Indian Agricultural Reformation Institute and Khadi and village industries commission, 15 (ii) The biogas produced in biogas plant is mixture of:, Hydrogen disulphide, and carbon dioxide., Hydrogen vapours, Methane and carbon monoxide., Hydrogen sulphide, Methane and carbon dioxide., Hydrogen disulphide, Methane and carbon dioxide., 15 (iii) Bacteria which help in biogas production is:, Lactobacillus, Bacillus sp., Methanobacterium, Escherichia coli, 15 (iv) Production of biogas involves:, Aerobic digestion of biomass with the help of bacteria., Anaerobic digestion of biomass with the help of bacteria., Both the above., None of the above., 15 (v) Assertion: Energy value of biogas is lower than that of organic matter., Reason: Biogas minimizes the chances of spread of faecal pathogens., Both the assertion and the reason are true and the reason is a correct explanation of the assertion., Both the assertion and reason are true but the reason is not a correct explanation of the assertion., Assertion is true but the reason is false., Both the assertion and reason are false., Read the following and answer any four questions from 16(i) to 16(v) given below: 4, SEX DETERMINATION, Sex determination results in the development of individuals with characteristics that allow them to be identified as males, females, or in some cases hermaphrodites. The first major breakthrough in understanding sex determination was the discovery of sex chromosomes in the early 1900s. From, meticulous analysis of male and female insect chromosomes, scientists discovered that, although most chromosomes (autosomes) were present in equal numbers in both males and females, there were one or two additional chromosomes (sex chromosomes) that were unequally represented in the two sexes. In many species, sex determination is genetic: males and females have different alleles or even different genes that specify their sexual morphology. In animals this is often accompanied by chromosomal differences, generally through combinations of XY, ZW, XO, ZO or haplodiploidy., 16(i) Which of the following is incorrect regarding ZW – ZZ type of sex determination?, It occurs in birds and some reptiles., Females are homogametic and males are heterogametic, 1:1 sex ratio is produced in the offsprings., Females are heterogametic and males are homogametic., 16 (ii) A couple has six daughters. What is the possibility of their having a girl next, time ?, 10 %, 50 %, 90 %, 100 %, 16(iii) Number of autosomes present in liver cells of a human female is, 22 autosomes, 22 pairs, 23 autosomes, 23 pairs, 16 (iv) Haplo-diplontic sex determination mechanism is found in, grasshoppers and cockroaches, birds and reptiles, butterflies and moths, Honeybees, ants and wasps., 16 (v) ZW sex chromosomes are seen in which organism?, Male birds, Female birds, Ants, Reptiles, SECTION B, What is self- incompatibility? Mention and explain any one strategy evolved in plants to prevent self pollination other than self incompatibility. 2, How do following respond to abiotic stresses:, a) Zooplankton b) Bacteria c) Polar bear d) Angiosperms 2, a) Write down the dual functions of AUG ?, b) Write any two STOP codons. 2, How do people living in high altitudes cope up with low oxygen present in the air? 2, Anand on a visit to under the ocean aquarium found that many sea anemones 2, are attached to hermit crab shells, clown fish living among the sea anemones ., He wondered whether these two associations are of same type, can you help, him to arrive at the correct conclusion ?, A child has sustained fever, stomach pain, loss of appetite and constipation. Doctor advised him to have WIDAL test. Identify the disease and name the causal organism. Mention two ways to prevent this disease. 2, OR, Give any two differences between a normal cell and a cancerous cell., Mention two ways by which ELISA can help in early detection of HIV infection. 2, What are palindromic DNA sequences? Write down palindromic sequence of 2, EcoRI., OR, What is meant by down stream processing ? Name the steps of down stream processing in case the biological product is a drug., Explain how a plant cell and an animal cell are made competent for transformation 2, with rDNA?, SECTION C, Give three hypothesis for explaining why tropical region show greatest level of species richness., OR, What do I,B,D and E signify in the above figure., Write down formula for calculating population density at time t+1 ., What will happen to population density if B+I is more than D+E? 3, Two snapdragon plants one with red flowers and other with white flowers are, crossed with each other, F1 progeny produced had pink flowers., Name the phenomenon responsible for it., What will be the genotype of F1 generation?, Find out genotypic and phenotypic ratio of F2 generation with the help of cross. 3, 3, Identify A, B and C in above diagram., Mention role of B in the above process., What is the unique feature of C?, IUDs are devices to prevent pregnancy. Name different types of IUDs along with one example each. Also mention their role as contraceptives. 3, Study the diagram showing replication of HIV in humans and answer the, following questions accordingly: 3, Write the chemical nature of the coat ‘A’. Name the molecule ‘X’ of the virus that enters inside the host cell., An enzyme ‘B’ is acting on molecule ‘X’ produce molecule ‘C’. Name ‘B’ and ‘C’, Mention the name of the host cell ‘D’ the HIV attacks first when it enters into the human body. Which cells of human body will be attacked next simultaneously by ‘E’?, SECTION D, Define megasporogenesis. Explain monosporic development of female, gametophyte along with well labelled diagrams., OR, Give a schematic representation of Spermatogenesis in humans., At which stage of life does gametogenesis begin in human male and female respectively?, Name the organs where gametogenesis gets completed in human male and female respectively. 5, Draw and explain how Alfred Hershey and Martha Chase proved that DNA is the genetic material., OR, Draw a neat and labelled schematic sketch of replication fork., Two blood samples A and B were picked from crime scene and handed to forensic department for DNA finger printing. Mention the steps involved in the process of DNA finger printing. How will it be confirmed whether the two samples are of same person or of two different persons? 5, a) Name and differentiate between the immunity provided by vaccination and, immunity provided by colostrum., b) Give one term for the proteins secreted by virus infected cells which protect, other cells from further infection?, c) Draw a well labelled diagram of H2L2 molecule., OR, Name the bacterium responsible for the large holes seen in "Swiss Cheese". What are these holes due to?, How are cyanobacteria used in the fields of paddy?, Why secondary treatment is also known as biological treatment?, Expand and define BOD., Why a small portion of activated sludge is pumped back into aeration tanks? 5, __________________________________________________________, MARKING SCHEME -2, BLUE PRINT-2, Sample paper 3, Class XII Biology (044) Theory, Time3 hours Maximum Marks: 70, General Instructions:, (i) All questions are compulsory., (ii) The question paper has four sections: Section A, Section B, Section C and Section D.There are 33 questions in the question paper., (iii) Section–A has 14 questions of 1 mark each and 02 case-based questions. Section–B has 9 questions of 2 marks each. Section–C has 5 questions of 3 marks each and Section–D has 3 questions of 5 marks each., (iv)There is no overall choice. However, internal choices have been provided in some questions. A student has to attempt only one of the alternatives in such questions., (v) Wherever necessary, neat and properly labeled diagrams should be drawn., SECTION A :-, An anther fails to produce viable pollen grains , give reason., What is the ploidy level of the PEN?, Who invented Automated DNA Sequencer?, At what phase the replication of DNA takes place?, For which disease the Widal test is conducted?, What is the source bacterium for the swiss cheese?, What is the molecular scissor?, Name the first transgenic cow?, Which bird exhibit brood parasitism?, There are 50000 rice varieties and 1000 varieties of mango cultivated in India. Which type of diversity is shown by these varieties?, Question number 11 to 14 are of assertion – reason type questions . Give the answers on the basis of any one option from the following., Assertion and Reason are correct and reason is the correct explanation of the assertion., Assertion and reason , both are correct , and reason is not the correct explaination of the assertion., Assertion is correct and reason is incorrect., Assertion is incorrect and the reason is correct., Assertion :- apple is considered as false fruit., Reason :- The fruit of apple is made by thalamus., Or, Assertion :- The perisperm is the remaining nucellus of the seed., Reason :- Nucellus has not been consumed by the developing embryo., Assertion :- in heterozygous genotype like “Tt” , only the dominant gene express the phenotype., Reason :- The dominant gene make complete protein and the recessive gene cannot make complete protein., Assertion :- In the Allergy, certain chemicals are released from mast cells, Reason :- Mast cells secrete chemicals like histamine and serotonin., Assertion :- The exponential growth is generally not found in the ecosystem, Reason :- for exponential growth , enormous raw materials are required , which not available in the ecosystem., Question number 15 and 16 are based upon the following paragraphs. Read the following paragraphs carefully and give the answers of any 4 questions from both question number 15 and question number 16., Each restriction endonuclease functions by inspecting the length of a DNA sequence . Once it finds its specific recognition sequence , it will bind to the DNA and cut each of the two strands of the double helix at specific points in their sugar – phosphate back bones . each restriction endonuclease recognizes a specific palindromic nucleotide sequence in the DNA. Palindromic sequence , are those points where the nucleotides are same in both the polarity of DNA., 15 A. The function of the restriction endonuclease enzyme is :-, To cut the DNA at certain points, To cut the DNA randomly at any points, To cut the DNA at palindromic sequence, To cut the DNA at terminal points., 15 B. To cut the double helix how many restriction endonuclease enzyme needed :-, 1 b. 2 c. 3 d . 4, 15 C . What make the back bone of the DNA :-, Pentose Sugar b. Phosphoric Acid c. Nitrogenous Base d. Both A and B, 15 D. A Palindromic sequence can be identified by :-, By the VNTR, by the repetition of the base pairs, by the same nucleotide pattern in opposite polarity, By the same nucleotide pattern in the same DNA strands, 15 E. Assertion :- After cutting of the DNA sticky end is get produced, Reason :- Restriction endonuclease cut the DNA by leaving some nucleotides remain unpaired., Assertion and Reason are correct and reason is the correct explanation of the assertion., Assertion and reason , both are correct , and reason is not the correct explaination of the assertion., Assertion is correct and reason is incorrect., Assertion is incorrect and the reason is correct., In species area relationship a graph is plotted between the area in the x axis and species in the y – axis by Alexander Von Humboldt. The graph was plotted after extensive explorations in the wilderness of South American jungles. There are two patterns of the graphs can be observed . a hyperbola and a slant line. For small ecosystem a hyperbola is obtained because after a particular expansion of the area no new species added to the ecosystem . whereas for the large ecosystem a slant line is obtained in the graph means there is still scope to add new species if the area will get increased., 16 A. which size of the ecosystem does the hyperbola obtained in graph :, Moderate size b. small size c. large size d. extreme large size, 16 B. In which curve , there is scope to add more number of the species in the area:-, 16 C. on which geographical area does the species area relationship is based :-, South America b. North America c. South Africa d. North Africa, 16 D. Who introduced the species area relationship:-, Alexander Flamming b. Alexander Von Humboldt. C. Alexander Mcqueen d. Alexander Graham Bell, 16 E. Assertion :- In tropical areas biodiversity is extremely rich., Reason :- A graph will give the slant line for the tropical regions, Assertion and Reason are correct and reason is the correct explanation of the assertion., Assertion and reason , both are correct , and reason is not the correct explaination of the assertion., Assertion is correct and reason is incorrect., Assertion is incorrect and the reason is correct., SECTION B :-, What is the difference between the pollination pattern of Vallisneria and water lily?, What is the trophoblast? what is the fate of trophoblast?, A mother wanted to pace gap between her two child , the doctor prescribed oral pills . enumerate how the oral pills will help the mother to achieve the same., In DNA the adenine is reported 20 % , calculate the quantity of the pyrimidine., What is the pleiotropy? Give a suitable example., At what stage the malarial parasite enter inside of the human body? Which plasmodium cause malignant malaria ?, Where the cultivation of Erythroxylum coca is yield? How the cocaine act in the consumer?, Fill in the blanks in the following table :-, What is the Rivet Popper Hypothesis? How it correlate with the loss of Biodiversity?, Or, What is invasion of alien species? Give 2 examples, where the alien species cause loss of Biodiversity., SECTION C :-, A. In the population of honey bees male honeybees have 16 chromosomes , whereas the female honeybees have 32 chromosomes. Justify the statement., B. distinguish between male heterogamety and female heterogamety with suitable example., A. How the transcription process between the prokaryotic cell is different from the transcription of eukaryotic cells?, B. Primary transcript of eukaryotic cells not able to translate. What are the conformational changes takes place in the primary transcript , to do its translation., How the genetic engineered insulin has been synthesized? How the genetic engineered insulin is superior than the pancreatic insulin?, What is RNA – i ? explain how the tobacco plants are protected by RNA – i ., Or, How the fragments of DNA can be separated after its digestion. Name the carcinogenic substance that used to colour the DNA., A microbiologist collected an unknown bacteria from nature and start culturing of the bacteria , which type of the growth pattern will be found for the bacteria before the culturing and after the culturing?, SECTION D :-, How many stages are found in the ovarian cycle? Explain each event with respect to the appropriate hormone?, Or, Study the diagram carefully and give the answers of following questions :-, What is the term given to the outer mass of the cells found around the ovum?, What is the term used for the membrane of the female gamete or ovum?, Which structure facilitate the sperm will introduce inside of the ovum?, Which structure of sperm facilitate the meiosis – II of the secondary oocyte?, Why sperm numer 2 and sperm number 3 fails to get enter inside of the ovum?, In the DNA – Fingerprinting , which part of the DNA used ? Why this particular part of DNA used ? Enumerate various stages of the DNA – fingerprinting., Or, Design a monohybrid cross which give same genotype ratio and phenotype ratio in f-2 generation. Give a suitable term for this monohybrid cross., What are the two types and reason of Thalassemia? Why Thalassemia is considered as Mendelian Disorder?(3+2=5), What type of genetic molecule is found in the HIV Virus? At which cells does it cause infection? Describe its method of infection in its target cell by diagram., Or, How the cancer is getting started? How benign tumor is different from malignant tumor? How the cancer can be detected? Give its methods of treatment?, MARKING SCHEME -3, SECTION A :-, An. Tapetum not able to provide nourishment ., ans. Triploidy, Ans. Fredrick Sanger, At S – Phase or Synthesis - phase, For Typhoid, Ans. Propionibacterium Sharmanii, Ans. Restriction Endonuclease or Exonuclease enzymes, Ans. Rosie, Ans. cuckoo or Eudynamus, Genetic Biodiversity, a. Or a., a., a., a., 15 A. The function of the restriction endonuclease enzyme is :-, Ans:- To cut the DNA at Palindromic sequence, 15 B. To cut the double helix how many restriction endonuclease enzyme needed :-, Answer :- 1, 15 C . What make the back bone of the DNA :-, Answer :- Both A and B, 15 D. A Palindromic sequence can be identified by :-, Answer :- By the same nucleotide pattern in opposite polarity, 15 E.a., 16 A. Which size of the ecosystem does the hyperbola obtained in graph :, nswer :- Small Size, 16 B. In which curve , there is scope to add more number of the species in the area:-, Answer :- Slant Line, 16 C. On which geographical area does the species area relationship is based :-, Answer :- South America, 16 D. Who introduced the species area relationship:-, Answer :- Alexander Von Humboldt, 16 E. A., SECTION B :-, Vallisneria perform cross pollination by water , and water lily perform cross pollination by wind. (1+1=2), Outermost layer of human embryo is called trophoblast, it produce the extra embryonic membrane called placenta. (1+1=2), Oral pills are made by oestrogen-progesterone preparation , which alter the hormonal level and mucus level in the uterus , hence inhibit the ovulation , implantation and retard the sperm entry. (1+1=2), If Adenine is 20 % then Thymine also 20 % so , the remaining 60% will be for Guanine and Cytosine , each with 30% . Pyrimidine means Cytosine and Thymine make together 50% of the total DNA., When a gene , express multiple characters , such property of the gene is called as pleiotropy. (1) for example disease called PhenylKetoNuria caused by a recessive gene and when the gene not synthesis any protein(enzyme) phenyl alanine not converted to Tyrosine, as a result of that several features like , mental retardation, reduction of hair and skin pigmentation and blackish urine get produced. (1), Sporozoit stage (1) , Plasmodium falciparum (1), South America (1) , Molecules of cocaine trigger or stimulate the dopamine receptors of CNS , which increase the energy level of the user.(1), Fill in the blanks in the following table :-, Answer :- Stanford Ecologist – Paul Ehrlich introduced the Rivet Popper Hypothesis , the Rivet means the species , and rivets are compared with screws of airplane , initial removal of the rivets or screws may not damage to the airplane but removal of the screws or rivets from crucial areas will lead to an accident of the air plane, that is of major ecosystem loss. (2), Or, Answer :- When an exotic species get entered in the local or any other ecosystem , such entry is called invasion of alien or exotic species. Example Parthenium or carrot grass and the water – hyacinth are the exotic plants , and create lot of extinctions to the other plants. (1+1=2), SECTION C :-, Male honey bees born with parthenogenesis . in which the ovum or female gamete directly develop into the male progeny. So the number of the chromosomes are 16. While female honey bees born from fertilized zygote and females are diploid , hence have 32 chromosomes.(1), B.- Male Heterogamety :- the formation of two types of gametes by males , is called as male heterogamety, such as human males produce 2 types of gametes , one with X-chromosomes and another with Y-Chromosomes. (1), Female Heterogamety:- The formation of two types of gametes by females , is called as female Heterogamety, such as female fowls or birds , produce two types of ova, one with Z – chromosomes and other with W- Chromosomes. (1), A. Answer :- a. Transcription in Prokaryotes need only DNA dependent RNA Polymerase. (any two) (1), Transcription in eukaryotes need the DNA Dependent RNA Polymerase – II enzyme., Transcription in Prokaryotes directly produce m-RNA ,, Transcription in Eukaryotes produce hn – RNA , then it converted to m- RNA., Transcription in Prokaryotes takes place in the cell cytoplasm., Transcription in the eukaryotes takes place in the nucleus., Transcription in Prokaryotes is coupled with translation., Transcription in eukaryotes not coupled with Translation., B. Answer :- Primary Trancripts in the eukaryotes is not able to translate because it is hn – RNA and hn – RNA consists of introns and exons both. Introns are non coding parts and exons are coding parts ., Splicing :- Removal of the introns as spliciosome is called as splicing., Capping and Tailing :- Addition of Methyl Guanosine tri phosphate at the 5 prime end of hn-RNA is called Capping and addition of 200-300 poly adenine at the 3 prime end is called as tailing. (2), Awer: - In the year 1983 American Pharmaceutical Company Eli Lilly, MADE Genetic Engineered Insulin is made by the help of triple protein chains as pro-insulin. When chain – C removed , only chain A and Chain B remains and connected by disulphide bonds , called insulin. (1), To make this insulin the gene for all 3 proteins isolated , then all the genes are made c-DNA , via reverse transcription , now the c-DNA introduced into e-coli , by the help of vector, and all 3 proteins obtained. (1), Genetic engineered insulin is different from pancreatic insulin , like pro-insulin form is present in the genetic engineered insulin whereas pro insulin form is absent in the pancreatic insulin., Genetic ingineered insulin can be stored and used according to the need , pancreatic insulin need to be used immediately., Genetic engineered insulin not has any side effects , whereas the pancreatic insulin has several side effects., Genetic engineered insulin can be obtained safely , where as the pancreatic insulin obtained after killing of an animal. (1), Answer :- RNA – i is the silencing of the RNA , so that it could not translate to protein and the expression of the gene can be stopped. (1), It is done in the tobacco plants , which get infested by nematode called Meloidegyne incognitia. But before the infection by nematode , a DNA of nematode introduced insude of the tobacco root cells , in such a way that both the strands transcribe , as a result of that , DNA produce sense and anti sense RNA. Both sense and antisense RNA combine to make ds- RNA. THE ds-RNA cleaved by the help of the DICER in to si-RNA or Short Interfering RNA . (1), Now when nematode cause infection to the tobacco roots , the si-RNA split down in to ss-RNA by a protein called RISC (RNA Interfering Silencing Complex) , hence the si-RNA converted to small ss –RNA. Now these ss- RNA will get binds with the m-RNA of the nematode and again ds-RNA produced. Which silence the targeted RNA. (1), Or, Answer :- Gel Electrophoresis is the technique to get separated to all the DNA fragments. The Gel Electrophoresis is the running of the DNA fragments in the agarose gel base and since the DNA being negatively charged so the DNA start moving towards the anode. Small DNA fragments move faster and larger DNA move slower. (2), Ethidium Bromide is the name of the carcinogenic substance , which is used to colour the DNA fragments.(1), A Answer :- Before culture :- Logistic Growth is found for the bacteria because the resources are limited in the ecosystem and the population grows only till carrying Capacity., After Culture :- Exponential growth is found for the bacteria because now no competition is there in the surrounding and plenty of resources also available in the medium. Now the size of the population will reach beyond the carrying capacity., SECTION D :-, answer :- There are 4 sub stages are found for the ovarian cycle , called a. menstruation phase . b. Proliferative Phase , c. Ovulatory Phase d. Luteal phase (1), Menstrual Phase :- Very less Progesterone level lead to the disintegration of the uterine layer and the sloughing off of dead ovum , uterine tissue, clotted blood , mucus found for 2 to 5 days. (1), Proliferative Phase :- Low level of progesterone send signal to the anterior pituitary gland to secrete FSH , as a result of that the damaged uterine layer get repaired and become thicker . the thickening of the uterine layer is called as proliferative phase . the FSH lead to produce more and more follicular cells around the secondary follicles. This stage found from day 6 to day 13. (1), Ovulatory Phase :- on 14th day or mid day of the ovarian cycle , the Anterior Pituitary gland produce huge amount of the Leutinising Hormone , as a result the secondary oocyte released out from the ovary. This event is called as Ovulatory phase. (1), Luteal Phase :- in the fourth phase the corpus luteum start releasing hormone Progesterone , this hormone is responsible for syngamy and to hold all the structures intact inside of the uterus. (1), Or, Ans. Corona Radiata, Ans. Zona Pelucida, Ans. Acrosome, ?Ans. Centriole, Zona pellucida get impermeable for the rest of the male gametes due to certain chemicals like antifertilisin., IAnswer :- Mini satellite DNA (1), Minisatellite DNA has VNTR , which is the base for the DNA fingerprinting. (1), Following are the stages involved in the DNA fingerprinting :- (3), Collection of cells :- WBC, Salivary Gland , Skin , Hair Follicle , Gametes, Extraction of the DNA :- Density Gradient Centrifugation, Digestion of DNA :- cutting by restriction endonuclease, Gel Electrophoresis :- Isolation of the DNA fragments on the gel plate., PCR :- Amplification of the DNA into multiple copies., Southern Blotting :- Transfer of the DNA fragments in the Nitro cellulosic sheet, Autoradiogram :- X-Ray detection of the Nitro cellulosic Sheet, Or, Anwer :- The cross of the Antirrhinum majus or Snapdragon plant upto f-2 generation , give the same ratio in genotype basis and phenotype basis , and that is 1:2:1, As the cross started with a red flowered plant (RR) with a white flowered plant (rr), In f-1 generation the genotype of the plants will be “Rr” and all the plants will produce Pink Coloured flowers., From f-1 generation plant , self cross has been conducted between two plants with the genotype “Rr” and in f-2 generation following genotypes ratio will obtained :-, RR – 25 %, Rr -50 %, Rr - 25%, Phenotypic Ratio :-, Red Flowerd Plants – 25 %, Pink coloured plants – 50 %, White coloured plants – 25 % (3 marks), Answer :- alpha thalassemia is caused by 2 gene HBA 1 and HBA 2 found in chromosome no. 11 and beta – thalassemia is caused by 1 gene HBB found on chromosome no. 16. (1), This is a gene controlled disease , hence it considered as mendelian disorder. (1), W:-, a. HIV is a retrovirus with single stranded RNA . (1), Initially HIV infects to the macrophages and later on Helper T cells. (1), Mode of reverse transcription in the macrophage cells as in P.N. 155 fig. 8.6 (3), Or, Answer :- a. by conversion of protooncogene to oncogene or from neoplastic cells (1), Benign Tumor :- Local tumor and not spread (1) Malignant Tumor :- Invasive tumor , spread to the another parts (1), Cancer can be diagnosed by Histopathology or Biopsy , CT-Scan , MRI etc. (1 ), Cancer treated by chemotherapy, radiotherapy, immunotherapy , surgery (1), Sample Paper 4, Class XII Biology (044) Theory, Time3 hours Maximum Marks: 70, General Instructions:, (i) All questions are compulsory., (ii) The question paper has four sections: Section A, Section B, Section C and Section D.There are 33 questions in the question paper., (iii) Section–A has 14 questions of 1 mark each and 02 case-based questions. Section–B has 9 questions of 2 marks each. Section–C has 5 questions of 3 marks each and Section–D has 3 questions of 5 marks each., (iv)There is no overall choice. However, internal choices have been provided in some questions. A student has to attempt only one of the alternatives in such questions., (v) Wherever necessary, neat and properly labeled diagrams should be drawn., SECTION A, MARKING SCHEME- 4, Sample paper 5, Class XII Biology (044) Theory, Time3 hours Maximum Marks: 70, General Instructions:, (i) All questions are compulsory., (ii) The question paper has four sections: Section A, Section B, Section C and Section D.There are 33 questions in the question paper., (iii) Section–A has 14 questions of 1 mark each and 02 case-based questions. Section–B has 9 questions of 2 marks each. Section–C has 5 questions of 3 marks each and Section–D has 3 questions of 5 marks each., (iv)There is no overall choice. However, internal choices have been provided in some questions. A student has to attempt only one of the alternatives in such questions., (v) Wherever necessary, neat and properly labeled diagrams should be drawn., MARKING SCHEME -5, Sample paper 6, Biology XII, Class XII Biology (044) Theory, Time3 hours Maximum Marks: 70, General Instructions:, (i) All questions are compulsory., (ii) The question paper has four sections: Section A, Section B, Section C and Section D.There are 33 questions in the question paper., (iii) Section–A has 14 questions of 1 mark each and 02 case-based questions. Section–B has 9 questions of 2 marks each. Section–C has 5 questions of 3 marks each and Section–D has 3 questions of 5 marks each., (iv)There is no overall choice. However, internal choices have been provided in some questions. A student has to attempt only one of the alternatives in such questions., (v) Wherever necessary, neat and properly labeled diagrams should be drawn., MARKING SCHEME-6