Question

Describe what happens after a pollen grain reaches the stigma

Answer 1

Only after pollination, when pollen has landed on the stigma of a suitable flower of the same species, can a chain of events happen that ends in the making of seeds. A pollen grain on the stigma grows a tiny tube, all the way down the style to the ovary. ... The ovary develops into a fruit to protect the seed.

Answer 2

When pollen grain reaches stigma , it creates a pollen tube which reaches the ovary . 

then the male gamete and the female gamete fuse to form zygote