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Reproduction in Lower and Higher Plants, , , , Multiple Choice Questions (1 Mark), , 1. The outer layer of pollen grain is thick and made up of complex, nonbiodegradable substance called as, (A) | lignin (B) cellulose, (C) pectin (D) sporopollenin, , 2. Sporoderm is made up of, (A) exosporium and endosporium, (B) outer integuments and inner integument, (C) testa and tegmen, (D)_ exine and intine, , 3. The number of meiotic and mitotic divisions necessary for development, of female gametophyte in angiosperms is 6, (A) 1 meiosis and 2 mitosis (B) 1 mitosis and 3 meiosis, (C) 1 meiosis and 1 mitosis (D) 1 meiosis and 3 mitosis, , 4. Identify the odd one with respect to pollinating agent., , , , (A) Baobab (B) Bottle brush, (C) Kadamb (D) Sausage, 5. In vitro pollen germination and pollen tube elongation can be induced, by :, (A) _ boric acid (B) glucose, (C) lactose (D) sucrose, , [Note: Sucrose is mostly used for pollen germination and pollen tube, elongation, however, Boric acid, glucose and lactose can also be used for, inducing in vitro pollen germination and pollen tube elongation.], , 6. Self-incompatibility is found in flowers of plants, , , , (A) Calotropis (B) maize, , (C) Thea (D) Gloriosa, 7. Porogamy refers to entry of pollen tube through, , (A) _ integuments (B) chalaza, , (C) micropyle (D) stigma, Std. XII Sci.: Biology
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Chapter 01: Reproduction in Lower, , , , , , , , , , , , and Higher Plants Target Publications” Pvt. Ltd., 8. is an example of helobial endosperm., (A) Adoxa (B) coconut, (C) Asphodelus (D) sunflower, , 9. The single shield shaped cotyledon in monocot seed is known as, (A) coleoptile (B) scutellum, (C) aleurone layer (D) perisperm, , 10. The example of dicot endospermic seed is, (A) _ castor (B) pea, (C) mango (D) bean, , Single Sentence Answers (1 Mark), , 1. Why anther is called as tetrasporangiate structure?, , Ans: Due to presence of four pollen sacs in dithecus anther it is called as, tetrasporangiate structure., , 2. At which stage pollen grains are shed from the anther in, Angiosperms?, , Ans: At two-celled stage pollen grains are shed from the anther in, Angiosperms., , 3. What is hilum with respect to ovule?, , Ans: Hilum is the point of attachment of funiculus to the main body of ovule., , 4. What is protandry?, , Ans: Protandry is a condition in which anthers mature first, but the stigma of, the same flower is not receptive at that time., , 5. | Name any one plant in which double fertilization was discovered?, , Ans: Lilium and Fritillaria [Any one plant], , 6. Why fertilization process in angiosperms is called as double, fertilization?, , Ans: In fertilization process of angiosperms, both the male gametes, participate, due to which fertilization occurs twice in the same embryo, sac, hence it is described as double fertilization., , Std. XII Sci.: Biology
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Chapter 01: Reproduction in Lower, and Higher Plants Target Publication Pie Lid, , 7. Which is the most common type of endosperm in angiospermic, families?, , Ans: Nuclear type is the most common type of endosperm found in, angiospermic families., , 8. What is the role of suspensor during the development of embryo?, , Ans: The suspensor helps in pushing the embryo in the endosperm., , 9. What is adventive polyembryony?, , Ans: In adventive polyembryony, embryos may develop from somatic, nucellus or integuments along with normal zygotic embryo., , 10. Name the hormone produced by unfertilised ovary responsible for, enlargement of ovary into fruit., , Ans: Auxin (Indole-3 Acetic Acid), , 2 Marks Questions, , 1. Draw a well labelled diagram of T.S. anther., , ANSE, ; Connective Epidermis |, | \, | |, Middle layers, ; Tapetum, | |, \ |, | |, | \, | |, Sporogenous tissue, | |, Endothecium, : T. S. of Anther, , [Four correct Labels % Mark each], , 2. Describe the structure of pollen grain., , Ans:, , i The process of formation of microspores from diploid microspore, mother cell through meiotic cell division inside the microsporangia or, pollen sacs is called microsporogenesis., , Std. XII Sci.: Biology
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Chapter 01: Reproduction in Lower, , and Higher Plants Target Publication Pvt Lis., , , , , , iil., , Structure of microspore: Pollen grain/microspore is a non-motile,, haploid, unicellular body with single nucleus. It is surrounded by a two, layered wall called sporoderm. The outer wall is called exine and the, inner wall is called intine., , Exine: The exine is thick and made up of complex, non-biodegradable,, substance called sporopollenin and it is resistant to chemicals., , It may be smooth or with a sculptured pattern (characteristic of the, species)., , At some places exine is very thin showing thin areas known as germpores., , Germ-pores are meant for the growth of emerging pollen tube during, germination of pollen grain., , , , , , , iv. Intine: The inner wall layer, intine consists of cellulose and pectin., [Each point % Mark], 3. | Draw a well labelled diagram of male gametophyte of angiosperms., Ans: SSCS i, ! !, |, |, \, | vt Pollen tube, Male gametes <7), | ;, Tube nucleus |, [Diagram - 1 Mark, Any two correct labels (male gamete,, tube nucleus and pollen tube) % Mark each], , 4. Describe the structure of female gametophyte of angiosperms., , Ans:, , i. In angiosperms, female gametophyte present in ovule is haploid, embryo-sac. Each embryo-sac contains egg apparatus, 3 antipodal cells, and 2 polar nuclei., , ii. Egg apparatus consists of large central, haploid egg cell and two, supporting haploid synergid cells. Synergid shows hair like projections, called filiform apparatus, which guide the pollen tube towards the egg., , iii. | Antipodal cells are group of three cells present at the chalazal end., , iv. The two haploid polar nuclei of large central cell fuse to form diploid, secondary nucleus or definitive nucleus, just prior to fertilization., , [4 points % Mark each], , Std. XII Sci.: Biology
