Question

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

Answer 1

Development of male gametophyte

1. Pollen grain/microspore marks the beginning of male gametophyte, thus it is the first cell of the male gametophyte.
2. It undergoes the first mitotic division to produce bigger, naked vegetative cells and small, thin-walled generative cells.
3. The vegetative cell is rich in food and having an irregular shaped nucleus.
4. The generative cell floats in the cytoplasm of the vegetative cells.
5. The second mitotic division is concerned with generative cells only and gives rise to two non-motile male gametes.
6. The mitotic division of the generative cells takes place either in the pollen grain or in the pollen tube.
7. The pollen grains are shed from the anther, at this two-celled stage in most of the angiosperms.