In angiosperms, a mature male gametophyte is derived from a pollen mother cell by

In angiosperms, a mature male gametophyte is derived from a pollen mother cell by one meotic and two mitotic divisions. In the pollen sac (microsporangium) of the anther haploid microspores are formed by meiosis. Mitosis then follows to produce a two-celled pollen grain with a small generative cell and a large vegetative cell. This generative cell will undergo further mitosis to form two male gametes (nuclei). The pollen tube grows through a spore in the pollen grain, with the tube (vegetative) nucleus at its tips and the male nuclei behind.