Explain the stages involved in the maturation of microspore into male gametophyte.

Pollen grain marks the begining of male gametophyte.

First Mitotic Division

1. During the initial mitotic division, it generates a larger, naked vegetative cell and a smaller, thinly-walled generative cell.
2. The vegetative cell is rich in food and having irregular shaped nucleus.
3. The generative cell floats in the cytoplasm of vegetative cell.

Second Mitotic Division

1. In the second mitotic division, the focus lies solely on the generative cell, resulting in the formation of two immobile male gametes.
2. This division occurs within either the pollen grain or the pollen tube.
3. The pollen grains are shed from the anther, at this two- celled stage in most of the angiosperms.