Male gametophytes and male gametes form in angiosperm

Question

How male gametophytes and male gametes formed in the angiosperms?

Answer 1

In the anthers of each stamen there are pollen sacs. In the pollen sacs there are microspore mother cells, micro-sporocytes. These cells undergo meiosis forming the microspores. Each microspore by the mitosis forms a pollen grain having one generative cell and one tube cell. The pollen grain is male gametophyte.

When pollination takes place and the pollen grain creates contact with stigma (the apex of pistil) the tube cell elongates its cytoplasm forming pollen tube which grows towards the ovary. The generative cell divides forming two sperm nuclei (or male gametes) which migrate through pollen tube.