The Male Gamete
In the anther, diploid mother cells undergo meiosis to form four haploid pollen grains. Each pollen grain develops a thick wall, often with an elaborate sculptured pattern characteristic of the particular species of flowering plant.
The nucleus within each pollen grain then divides into two by mitosis to form a generative nucleus and a pollen tube nucleus. The generative nucleus divides further to form two male nuclei which function as male gametes