Question

Explain the process of sexual reproduction in plants beginning at pollination (double fertilization)?

Answer 1

The pollen tube enters in the ovule by piercing stigma and style. Finally, the tube enters into the ovule through the micropyle.

Explanation:

1. The pollen grain germinates at the stigma and forms pollen tube. The pollen tube increases in length and enters to the ovule by piercing tissues of stigma and style from micropyle. Two male gametes are discharged into the embryo sac.
2. One male gamete fertilize the egg cell, while other unite with secondary nucleus. This event is double fertilization, because two male gametes unite here.
3. The fusion of other male gamete with the secondary nucleus is triple fusion. It is because here three nuclei two from secondary nucleus and one from male unite. Thank you