DENDROLOGY

Detailed explanation-1: -Each pollen grain contains vegetative germ cells, that is, non-germ cells and one germ cell or germ cell. In flowering plants, vegetative cells produce pollen tubes, which divide to form two sperm nuclei.

Detailed explanation-2: -Pollen grains are the male germ cells of plants, released to fertilize the corresponding female plant parts.

Detailed explanation-3: -Mature pollen grains contain two cells: a generative cell and a pollen tube cell. The generative cell is contained within the larger pollen tube cell. Upon germination, the tube cell forms the pollen tube through which the generative cell migrates to enter the ovary.

Detailed explanation-4: -Each pollen grain contains vegetative (non-reproductive) cells (only a single cell in most flowering plants but several in other seed plants) and a generative (reproductive) cell. In flowering plants the vegetative tube cell produces the pollen tube, and the generative cell divides to form the two sperm nuclei.