A pollen grain in angiosperm at the time of dehiscence from an anther could be 2-celled or 3-celled. Explain, how are the cells placed within the pollen grain when shed at a 2-celled stage?

In most of the angiosperms, pollen grains released at 2-celled stage. Pollen grain contains a small generative and a large vegetative cell. At 3-celled stage pollen grains contains one vegetative cell and two male gametes are present.