Q.9 The generative cell of two-celled pollen divides in the pollen tube, but not in three-celled pollen. Give reasons.
In over 60 % of angiosperms, pollen grains are shed at this 2-celled stage tube ceil or vegetative cell generative cell. In the remaining species, the generative cell divides mitotically to give rise to the two male gametes before pollen grains are shed tubercle or vegetative cell two male gametes 3-celled stage.
In 3 celled stage, the pollen grains further germinate on the stigma to produce pollen tube through ane of the germ pores. The contents of the pollen grains rove into the tube pollen tube grows through the tissues of the stigma and style and reaches to ovary. Implants, when pollen grain are shed at 2 celled stage the generative cell divides and form two male gametes during the growth of the pollen tube in the stigma.
