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Class-12 Sub : Biology Chapter : Sexual Reproduction in Flowering Plants MODEL QUESTIONS WITH ANSWER Multiple choice questions ( carrying 1 mark ) 1 .In angiosperm female gametophyte is: a) Embryo b) Egg Apparatus c)Embryo sac d) synergids Ans: c)Embryo sac 2. Exine layer of pollen grain is made up of : a) sporopollenin b)Pectin c) cellulose d)chitin Ans: a)sporopollenin 3. Embryo sac of angiosperm is : a) 6-celled 8-nucleate b) 7-celled 8-nucleate c)8-celled 7- nucleate d)7-celled 7-nucleate Ans: b) 7-celled 8-nucleate 4. Microsporogenesis is the formation of : a) Microspore b) Megaspore c) Egg d) Embryo sac Ans : a) Microspore 5 . Pollination by insect is called: a) Hydrophily b) Entomophily c) Anemophily d) Ornithophilly Ans: Entomophily 6 . Removal of anther is called: a) Emasculation b) Bagging c) Artificial hybridization d) pollination Ans: a) Emasculation 7 . Which layer of microsporangium provides nutrition to the developing pollen grains: a) Epidermis b) Endothecium c) Tapetum d) All Ans : c) Tapetum 8 . The transfer of pollen grains from anther to stigma is called; a) Fertilization b) pollination c) Microsporogenesis d) Polyembryony Ans. b) Pollination 9 . Occurrence of more than one embryo in a seed is known as: a) Polyembryony b) parthenocarpy c) Apomixis d) Embryogeny Ans: a) Polyembryony 10 . A typical angiospermic anther is; a) Bilobed b) unilobed c) Trilobed d) Tetralobed Ans: a) Bilobed II. Very short questions (carrying 2 marks) Q1. Name two cells of a mature pollen grain? Ans: Vegetative cell and Generative cell Q2. What do you mean by parthenocarpy? Ans: Formation of fruit without fertilization is known as parthenocarpy. Q3. What are the different types of endosperm? Ans: Nuclear endosperm and Cellular endosperm Q4. What is meant by monosporic development of female gametophyte? Ans: The method of embryo sac formation from single megaspore is called monosporic development. Q5. What are cleistogamous flowers? Ans: The flower which are always closed and shows autogamy is known as cleistogamous flower. Q6. Name the parts of angiospermic flowers in which development of male and female gametophyte takes place. Ans: Anther and Ovary Q7. What do you mean by monoecious and dioecious plants? Ans: Plants that have both male and female sex organs or flowers are called monoecious plant whereas a dioecious plants have either male or female sex organ. Q8. Differentiate between hypocotyl and epicotyl. Ans: The part of embryonal axis below the cotyledon is known as hypocotyl whereas the part of embryonal axis above the cotyledon is known as epicotyl. Q9. Why apple is called a false fruit? Ans: Apple is a false fruit because thalamus develops into fruit here ,not the ovary. Q10. What is seed dormancy? Ans: Seed dormancy is a state in which seeds are prevented from germinating even in favourable environmental condition. III. Short answer type question (carrying 3 marks) Q1. Draw a labelled diagram of an embryo sac. Ans: Figure : An Embryo Sac Q2. What is triple fusion? Name the nuclei involved in triple fusion. Ans: Fusion of male gamete with diploid secondary nucleus to form triploid primary endosperm nucleus is known as triple fusion. In triple fusion two polar nuclei and one male gamete are involved. Q3. Mention three strategies evolved to prevent self-pollination in flowers. Ans: 1. Dichogamy: stigma and anther mature at different times. 2. Heterostyly: stigma and anther are placed at different levels. 3. self-incompilibility Q4. What do you mean by double fertilization? Ans: The process of fusion of one male gamete with egg to form diploid zygote and another male gamete with the polar nuclei or secondary nucleus to form primary endosperm nucleus is called double fertilization. Q5. Differentiate between microsporogenesis and megasporogenesis. Ans: Microsporogenesis Megasporogenesis It is the formation of haploid microspores It is the formation of haploid megaspore from the diploid microspore mother cell. from the diploid megaspore mother cell. The microspores are arranged in tetrahedral The megaspores are arranged in linear tetrad. tetrad. All the microspores are functional. Only one megaspore is functional. IV. Long answer type question( carrying 5 marks) Q1. With neat, labeled diagram, describe the parts of a typical angiospermic ovule. Ans: A typical angiospermic ovule has following parts: 1. Funicle: Stalk by which ovule is attached to placenta. 2. Hilum: Junction between ovule and funicle 3. Integument: Protective envelopes around ovule 4. Micropyle: A small opening at the tip of integuments. 5. Chalaza: Basal part of ovule. 6. Nucellus: Mass of cells enclosed in integuments having reserve food material. 7. Embryo sac or Female gametophyte: Located in nucellus. Q2. What do you mean by pollination? Explain the differents types of pollination. Ans: The transfer of pollen grains from anther to stigma of a pistil is called pollination. Types of pollination: 1. Autogamy: Transfer of pollen grains from anther to stigma of the same flower. E.g viola,oxalis 2. Geitonogamy: Transfer of pollen grain from the anther to the stigma of another flower of the same plant. E.g cucurbits 3. Xenogamy: Transfer of pollen grains from anther to the stigma of another flower of the different plant. E.g papaya Q3. Explain the process of microsporogenesis in angiosperm. Ans: The process of formation of haploid microspores from a pollen mother cell (PMC) or microspore mother cell through meiosis is called Microsporogenesis. When the anther develops, each cell of sporogenous tissue functions as microspore mother cell (MMC) which undergoes meiotic divisions to form four haploid microspores . The microspores get arranged in a cluster of four cells which is known as microspore tetrads. As the anther matures and dehydrates, the microspores dissociate from each other and develop into pollen grains. Fig: Microsporogenesis Prepared by Dolly Dey PGT Biology S S + 2 High School Patamda East Singhbhum .
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