Botany - Sexual Reproduction in Flowering Plants Question with Solution | TestHub

In Angiosperms, pollen grain is the first male gametophyte. 

Microspore divides mitotically forming two cells.
1. Vegetative cell: Bigger in size having abundant food reserve and large irregularly shaped nucleus.
2. Generative cell: Small and floats in the cytoplasm of the vegetative cell. It is spindle-shaped with dense cytoplasm and nucleus.
Shedding of pollen grains takes place at this two-celled stage in 60 % of angiosperms. In rest, the generative cell divides to form the male gametes (sperms) and pollen is shed at the three-celled stage.