Which of the following is not a post-fertilisation event? (A) Endospe…

The correct answer is Option (4) → Only E

Post-fertilisation events are the events that follow double fertilisation: endosperm development, embryo development, maturation of ovules into seeds and maturation of the ovary into a fruit. Anything that happens before fertilisation is not one of them.

(A) Endosperm development. — A post-fertilisation event. The primary endosperm cell formed by triple fusion develops into the endosperm.

(B) Maturation of ovule(s) into seed(s). — A post-fertilisation event.

(C) Maturation of ovary into fruit. — A post-fertilisation event; it proceeds along with seed formation.

(D) Embryo development. — A post-fertilisation event. The zygote develops into the embryo.

(E) Pollen grains development. — Not a post-fertilisation event. Pollen grains develop in the anther before pollination, so this is a pre-fertilisation event.

So only E is not a post-fertilisation event.

NCERT Extract:
Post-fertilisation: Structures and Events – “Following double fertilisation, events of endosperm and embryo development, maturation of ovule(s) into seed(s) and ovary into fruit, are collectively termed post-fertilisation events.”
Stamen, Microsporangium and Pollen Grain – “… As the anthers mature and dehydrate, the microspores dissociate from each other and develop into pollen grains (Figure 1.3 b).”