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Q1. Define Binary Fission., , Ans: This process takes place in unicellular organisms. Parent cell elongates and gets, divided into two identical daughter cells. Each daughter cell grows into an independent adult., Q2. Define Endospore Formation., , Ans: In this method the spore wall is formed around a bacterial cell to form an endospore., This endospore germinates to form an active bacterium under favourable conditions., Q3. Define Fragmentation., , Ans: In this process, body of the organism breaks up into two parts. Then each part grows, into a new filament thus forming two organisms from a single one., Q4. Define Spore Formation., , Ans: The spores are tiny spherical unicellular structures protected by thick wall. The spores are, stored in a hard outer covering and this is called sporangium. Under favourable conditions the, hard cover breaks and spores spread for germination., , Q5. Define Budding., , Ans: In yeast, new organisms are produced by the bud formation from the Parent organism., After growing to full size, the bud gets detached and forms a new independent individual., , Q6.Define Vegetative propagation:, , Ans: When vegetative parts of a plant like stems, leaves and root etc., give rise to new ones, it, is.called vegetative propagation., , Q.7. Explain what you understand by sexual reproduction., , Ans.Sexual reproduction means involvement of two parents in the process of reproduction. It is, found mainly in higher plants where male gamete and female gamete fuse to form a zygote., These zygotes develop into individuals which are not identical. Offsprings inherit the, , characteristics of both the parents. In sexual reproduction both parents survive after the, process of reproduction., , Scanned with CamScanner
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Q.8. State the main difference between asexual and sexual reproduction., , , , , , , , Ans., Asexual reproduction Sexual reproduction, (a) Only one parent plant is involved. (a) Both male and female parents are, involved., (b) Occurs in unisexual plants. (b) Occurs in bisexual plants., (c) Occurs in lower plants. (c) Occurs in higher plants., (d) Reproductive organs are not hd) Fully developed reproductive parts, present. are present., (e) In most of the methods the (e) Original parents remain alive after, original parent disappears. Process of reproduction., (A Process like gamete formation or (A Fertilization of gametes give rises to, fertilization is not seen. zygote., (9) Characteristics of only one parent (g) Characteristics of both parents are, is inherited. . inherited., (h) No need of seeds. (h) Seeds are used to get new plants, from a flower., , , , , , Q.9.Sketch the reproductive parts of a flower., , Ans., Stigma ~, Anther Style:, Ovule’, Ovary, Filament ., (a) Stamen (b) Pistil, , (Male reproductive part) (Female reproductive part), , Scanned with CamScanner
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rig: 1a.U, , Q.10.Explain the difference between self-pollination and cross-pollination, Ans., , , , , , , , , , Self-Pollination Cross-Pollination, , (a) Pollen grains are transferred to Pollen grains are carried to stigma, the stigma of the same flower. of another flower. :, , (b) Occurs in bisexual plants having Occurs in bisexual flowers having, anther and stigma maturing at anther and stigma maturing at, same time. different times., , (c) It takes place in plants like It takes place in plants like ladywheat, peas etc. finger, tomato, brinjal etc., , , , , , Q.11How does the process of fertilization take place in flowers?, Ans.When the pollen grain reaches the stigma of a same species flower, it starts, , growing out into the pollen tube of the stigma. This tube continues to grow inside the style till it, reaches the ovule. Male cells are released into the ovule for the fertilization with the female egg, cell and thus the zygote is formed. After this process of fertilization, the ovary develops into, fruit and ovule into seeds., , Q.12. Describe the various ways by which seeds are dispersed., , Ans. Following are the ways in which the seeds are dispersed:, , (i) Some light seeds like that of madar, which are hairy, dry and small are carried away by the, wind to different places., , (ii) Spiny seeds and fruits like that of xanthium and urena, stick to the clothes of passers by and, animals. These seeds are carried away by these agents to different places., , (iii) In some plants having heavy seeds like that of coconut, water acts as the dispersing agents., (iv) Some seeds are dispersed with the fruit burst like in case of balsam and castor., , Scanned with CamScanner
