Question

What is meant by pollination? Explain the structure of a germinating pollen grain with the help of a labelled diagram.

Answer 1

• Pollination is the process by which the pollen grains from the anther are transferred to the stigma of a flower of the same species.
• The two types of pollination are self-pollination and cross-pollination.

The germinating pollen grain takes the following course:

• After reaching the stigma of the same kind of plant(same species), the pollen grain absorbs moisture from the stigma surface and begins to grow a tube. This tube is called a pollen tube.
• The pollen tube lengthens through the style and enters the ovule through the ovary. There it releases its male gamete which fuse with the female gamete inside the ovule to form the zygote.