The generative cell of two-celled pollen divides into the pollen tube but not in three-celled pollen. Give reasons.
In three-celled pollen, one of the cells is a vegetative cell that has no role to play in fertilization. The remaining two cells are the male gametes, and they are the actual participants in fertilization. Rather than the vegetative cells, the generative cells divide inside the pollen tube.
In 60% of the cases, the generative cell divides inside the pollen tube. In the remaining case, the generative cell divides much before pollination.