Formation of Vegetative and Generative Cells
The division of a pollen grain results in two unequal cells-the vegetative cell and the generative cell. The pollen grain is hereafter known as the male gametophyte because both the cells of this structure carry a single set of chromosomes. Do you recall that gametophyte represents the haploid generation of the life cycle of plant? The larger cell is the vegetative cell and it forms the pollen tube. The smaller cell is known as the generative cell and it produces two sperms by a mitotic division. The position of the generative cell is related to that of the microspore nucleus and the orientation of the spindle. In Figure that before division the pollen nucleus migrates to one side of the pollen grain and comes to rest near the wall. The division involves the formation of an unusual spindle structure.
Figure: Formation of Vegetative and Generative Cells