Question

60% of angiosperms, pollen grains shed at 2 celled stage, but in some species pollen grains are shed at 3 celled stage.

1. Distinguish between 2 celled and 3 celled stage of pollen grains?

2. Give the significance of germ pore of exine surface

Answer 1

1. In 2 celled stage pollen grains contains two cells – bigger vegetative cell and smaller generative cell. In 3 celled stage, pollen grains contains 3 cells vegetative cell and 2 male gametes

2. Germ pore is the opening through which pollen tube come out during pollen germination