Q1 of 57 Page 77

i) Name the process by which a fruit is developed.

ii) Explain the development process in brief.


iii) Draw a neat, labelled diagram of that process.


(i) By the process of fertilization the fruit is developed. Fertilization is the process of fusion of male and female gametes to form the zygote.

(ii) Development process:-


1. Germination of pollen grains: - by the process of pollination pollen grain when lands on suitable stigma. Pollen has 2 cells. One is vegetative cell and other is a generative cell. Vegetative cell forms the pollen tube which carries the generative cell which later gets divided into 2 male gametes.


2. Fertilization: - through micropyle pollen tube enters the embryo-sac and releases the male gametes in it. Then fusion between male and female takes place which forms the zygote. This process of fusion is known as the fertilization.


3. Triple fusion: - Fusion of male gamete with the secondary nucleus to form endosperm nucleus is known triple fusion. This is known as triple fusion because in this two polar nuclei fuse with the male gamete hence the result (endosperm nucleus) which we get after fusion is triploid in nature.


4. Double fertilization: - There are two male gametes. One male gamete fuses with the egg to form a zygote. This fusion between male and female gametes is known as fertilization. And the second male gamete fuses with secondary nucleus to form the endosperm nucleus. This process of fusion of male gamete with egg and secondary nucleus is known as double fertilization.


5. Post- fertilization changes: - (A) ovule → seeds


(B) Integuments → seed coats


(C) Ovary → Fruit.


(iii)



More from this chapter

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19

Use words from the given list to complete the following paragraph. (The words may be used once / more than once / not at all).

(seed, fruit, pollination, dispersal, germination, fertilization, flower, reproduction)


Ramu went to the field along with his father. He sowed mustard seeds in the soil. After a few days, he observed the process of _______ _. The seeds grew into plants and produced ________. On maturity, these flowers produced pollen grains that were transferred to the stigma by _______ _. The male gametes fused with the female gametes during the process of _______ _.


 20

Coconut seeds are dispersed by Hydrochory (dispersal by water). Mention the part of the fruit whose modification help in this mechanism.

 2

Write the two events involved in the sexual reproduction of a flowering plant.

i) Discuss the first event and write the types.


ii) Mention the advantages and the disadvantages of that event.


 3

i) Fruit is the product of fertilization. Is there any fruit which is formed without the act of fertilization?

ii) Represent the classification of fruits in a diagrammatic sketch.