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© CBSEPracticalSkills.com Edulabz International REPRODUCTION IN PLANTS 12 TEXTBOOK QUESTIONS AND THEIR ANSWERS Q.1. Paheli has never seen the seeds of sugarcane, potato and rose. She wants to know how these plants reproduce. Ans. The above plants reproduce by means of asexual reproduction. 1. In asexual reproduction, plants can give rise to new plants without seeds. 2. So, new plants are produced from roots, stem, leaves and buds. 3. In sugarcane and rose, new plants develop from stems while in potato, new plants develop from eyes or buds. Q.2. Bhoojho wants to know if there is any advantage of vegetative propagation. Ans. Plants produced by vegetative propagation. It takes less time to grow and bear flowers and fruits earlier than those produced from seeds. CBSEPracticalSkills.com 1 © Edulabz International © CBSEPracticalSkills.com Edulabz International Q.3. Boojho wants to know how the male gamete in the pollen grain reaches the female gamete present in the ovule. Ans. By the process of pollination. Q.4. Boojho wants to know why flowers are generally so colourful and fragrant. Is it to attract insects ? Ans. Most of the flowers are highly coloured and strong smelling to attract insects, which help in the process of pollination. Q.5. Fill in the blanks : (a) Production of new individuals from the vegetative part of parent is called _____. (b) A flower may have either male or female reproductive parts. Such a flower is called _____. (c) The transfer of pollen grains from the anther to the stigma of the same or of another flower of the same kind is known as ___. (d) The fusion of male and female gametes is termed as ___ . CBSEPracticalSkills.com 2 © Edulabz International © CBSEPracticalSkills.com Edulabz International (e) Seed dispersal takes place by means of ___________ and _____. Ans. (i) Vegetative propagation, (ii) Unisexual flower, (iii) Cross-pollination, (iv) Fertilization, (v) Wind, water, animals. Q.6. Describe the different methods of asexual reproduction. Give examples. Ans. There are several methods of asexual reproduction such as vegetative propagation, budding, fragmentation and spore formation. (a) Vegetative propagation : In this type of asexual reproduction new plants are produced from the roots, stem, leaves and buds. For examples, rose, sugar cane, money plant etc. (b) Budding : In the yeast plant, small bulb like projections come out from the yeast cell which are called bud. The bud gradually grows and gets detached from the parent cell and forms a new yeast cells. The new yeast cell grows, mature and produces more yeast cells. This process is called budding. CBSEPracticalSkills.com 3 © Edulabz International © CBSEPracticalSkills.com Edulabz International (c) Fragmentation : In this type of asexual reproduction, algae grow and multiply rapidly by fragmentation with the availability of water and nutrients. An alga breaks up into two or more fragments. These fragments or pieces grow into new individuals. (d) Spore formation : In this type of asexual reproduction fungi grow from spores. The spores are asexual reproductive bodies. Each spore is covered by a hard protective coat to withstand unfavourable conditions such as high temperature and low humidity. Under favourable conditions, a spore germinates and develops into a new individual. Plant such as moss and fern also reproduce by means of spores. Q.7. Explain what do you understand by sexual reproduction. Ans. In sexual reproduction, both male and female parts take part in the reproduction. In this process, a male and a female gamete fuse to form a zygote. Thus, for sexual reproduction two parents are required to produce one new individual. Q.8. State the main difference between sexual and asexual reproduction. Ans. Sexual reproduction CBSEPracticalSkills.com Asexual reproduction 4 © Edulabz International © CBSEPracticalSkills.com 1. New plants are obtained from seeds. 2. Two parents are required to produce an individual. 3. Takes place with the help of specialized cells. 4. New individual has characters of both the parents. Edulabz International 1. Plants can give rise to new plants without seeds. 2. The new individual comes from a single parent. 3. No cells are required. 4. Characters of the new individual are same as that of the only parent. Q.9. Sketch the reproductive parts of a flower. Ans. Q.10. Explain the difference between self-pollination and crosspollination. CBSEPracticalSkills.com 5 © Edulabz International © CBSEPracticalSkills.com Edulabz International Ans. Self pollination Cross pollination 1. In self-pollination, pollen grains are transferred from the anther to the stigma of the same flower. 2. In self-pollination, no agency is required. 3. Occurs only in bisexual flowers. 1. In cross-pollination, pollen grains are transferred from the anther of one flower to the stigma of another flower of the same kind. 2. Agencies like wind, air or insects are required. 3. Occurs in both unisexual and bisexual flowers. Q.11. How does the process of fertilization take place in flowers ? Ans. Pollen grain reaches on the stigma of pistil by pollination. On the stigma, the pollen grain germinates and a pollen tube CBSEPracticalSkills.com 6 © Edulabz International © CBSEPracticalSkills.com Edulabz International comes out. This pollen tube grows and approaches through the style to ovary carrying male gametes with it, where it enters the ovule. Inside the ovule, there is female gamete or egg. The male, gamete fuses with the female gamete. This process is called fertilization. Q.12. Describe the various ways by which seeds are dispersed. Ans. Seeds and fruits of plants are carried away by wind, water and animals. Winged seeds such as those of drumstick and maple, light seeds of grasses or hairy seeds of aak (Madar) get blown off with the wind to far away places. Some seeds are dispersed by water. These seeds usually develop floating ability in the form of spongy fibrous outer coat as in coconut. Some seeds are dispersed by animals, especially spiny seeds with hooks which get attached to the bodies of animals and are carried to distant places. Some examples are Xanthium and Urena. Some seeds are dispersed when the fruit burst with sudden jerks. The seeds are scattered far from the parent plant. Examples, caster and balsam. CBSEPracticalSkills.com 7 © Edulabz International © CBSEPracticalSkills.com Edulabz International Q.13. Match items in column I with those in column II. Column I Column II (a) Bud (i) Maple (b) Eyes (ii) Spirogyra (c) Fragmentation (iii) Yeast (d) Wings (iv) Bread mould (e) Spores (v) Potato (vi) Rose Ans. Column I Column II (a) Bud (iii) Yeast (b) Eyes (v) Potato (c) Fragmentation (ii) Spirogyra (d) Wings (i) Maple (e) Spores (iv) Bread mould Q.14. Tick (9) the correct answer : (a) The reproductive part of the plant is the CBSEPracticalSkills.com 8 © Edulabz International © CBSEPracticalSkills.com (i) leaf (ii) stem (iii) root (iv) flower Edulabz International Ans. (iv) Flower. (b) The process of fusion of the male and the female gametes is called (i) fertilization (iii) reproduction (ii) pollination (iv) seed formation Ans. (i) Fertilization. (c) Mature ovary forms the (i) seed (iii) pistil (ii) stamen (iv) fruit Ans. (iv) Fruit. (d) A spore producing plant is (i) rose (iii) potato CBSEPracticalSkills.com (ii) bread mould (iv) ginger 9 © Edulabz International CBSEPracticalSkills.com © Edulabz International © Edulabz International Ans. (ii) Bread mould. (e) Bryophyllum can reproduce by its (i) stem (ii) leaves (iii) roots (iv) flower Ans. (ii) Leaves. CBSEPracticalSkills.com 10