Question

Describe the process of development of male gametophyte in angiosperms.

Answer 1

1. In flowering plants or angiosperms, pollen grains represent greatly reduced haploid male gametophyte production.
2. While remaining within the pollen sac, the pollen grain begins to germinate. The pollen grain goes through its first mitotic division, producing larger vegetative cells and smaller generative cells.
3. The pollengrain at this two celled stage transferred on stigma due to act of pollination.
4. The pollengrain undergoes the second mitotic division of the generative cell on stigma. The generative cell produces two non-motile gametes.
5. The intine develops out via a germpore to produce a pollen tube when the pollen grain absorbs water.
6. The nucleus as well as two male gametes enter the pollen tube.
7. Male gametophyte is a germinated pollen grain with a pollen tube and two male gametes.
8. The male gametes are non-motile and carried through in pollen tube upto the egg or ova. it is known as siphonogamy.