Megagametogenesis - The nucleus of a functional megaspore divides mitotically to produce four or more nuclei.

In most plants, megaspore nucleus undergoes three mitotic division to produce 8 nuclei.

Egg cell and two synergids situated on its side. 3 are antipodal cells and two remain in centre , polar nuclei, fuses to form secondary nucleus. The magspore thus develops into a mature megagametophyte or embryo sac.

Microgametogenesis - This refers to the production of male gamete or sperms. During maturation of pollen, the microspore nucleus divides mitotically to produce generative and vegetative cells.

Pollen is released with  binucleate stage . When pollen lands into stigma  of flower it is known as pollination. Shortly, after pollination the pollen germinate and pollen tube enters the stigma and grows through style.

The generative nucleus undergoes mitotic division to produce 2 male gametes or sperms. The pollen along with pollen tube known as microgametophyte.