Question

(a) Why is the process of fertilisation in angiosperms termed as double fertilisation? Explain.
(b) Draw a diagram of an angiospermic embryo-sac where fertilisation is just completed. Label the following parts:
(i) Micropylar end of the embryo-sac
(ii) The part that develops into an embryo
(iii) The part that develops into an endosperm
(iv) The degenerating cells at the chalazal end
(c) Draw a labelled diagram of globular embryonic stage of an angiosperm.

Answer 1

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(a) The process of fusion of male gamete with the female gamete to form the diploid zygote (2n) is known as fertilisation. The fusion of one male gamete with egg and that of another male gamete with a secondary nucleus is called double fertilisation. It is the characteristic feature of only angiosperms. All angiosperms are characterised by a unique process called double fertilisation.

(b) see attachment

Answer 2

Answer:

Why is the process of fertilisation in angiosperms termed as double fertilisation? Explain.

(b) Draw a diagram of an angiospermic embryo-sac where fertilisation is just completed. Label the following parts:

(i) Micropylar end of the embryo-sac

(ii) The part that develops into an embryo

Explanation: