DENDROLOGY

Detailed explanation-1: -The generative cell then separates from the pollen grain wall and is engulfed by the vegetative cell, resulting in a unique ‘cell within a cell’ structure. In angiosperms, gametogenesis leads to the formation of male gametes in two stages: Microsporogenesis.

Detailed explanation-2: -The generative cell is formed at the first division of the microspore and divides in the pollen grain or pollen tube to form two sperm cells.

Detailed explanation-3: -Vegetative cell is the largest cell of male gametophyte in plants. It stores food and produces pollen tube. It is usually called tube cell not at fixed time as it develops pollen tube during the pollen pistil interaction to deliver the sperm nuclei inside the embryosac.