6 Meenal went to a 'plant nursery' with her mother. She was very happy to see different varieties of plants in the nursery. The gardener approached them and asked about their choice of plant. Meenal's mother wanted a flowering plant with fragrance. The gardener showed them a plant and told them that this variety has been prepared by a method of vegetative propagation of stems. (a) What is vegetative propagation and why is it called so? (b) Name two artificial methods of vegetative propagation from stem. (c) Write one advantage and one disadvantage of vegetative propagation over sexual reproduction (d) What is the difference between sexual and asexual reproduction?
Answers
Answer:
a) Vegetative reproduction is a method of reproduction in which new plantlets are formed from vegetative parts like leaf, stem, root without involvement of sexual part flower.
b) Two methods of artificial vegetative propagation using stem-
● Grafting- Usually shaft (desired plant's stem) is grafted over stolon (parent plant's stem). Eg- Mango, Rose.
● Layering- Parent plant's stem is pegged in soil and from there new branch arises as new plants. Eg- Jasmine.
c) ● Advantage - Requisite parental character is obtained, pureline can be achieved.
● Disadvantage- No variation as no sexual reproduction and may result in extinction of the species if any mutation occurs.
Hybrid in terms of genetic characteristics can't be formed.
d) In sexual reproduction there is fusion of gemetes and involvement of gamete. But in asexual it there is no fusion gametes but gamete formation may be there.
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