Question

what is mean by pollination? explain the structure of a germinating Pollen Grain with the help of a labelled diagram

Answer 1

Pollination is the transfer of pollen from a male part of a plant to a female part of a plant, enabling later fertilization and the production of seeds, most often by an animal or by wind.

The picture of pollination flower you can see in the ncert or any science book.

Answer 2

Pollination is the process of transfer of the pollen grains from the anther to the stigma of the same flower or another flower of other plant but of the same species.
Pollination is of two types- Self pollination and cross pollination.

A germinated pollen grain has the the following parts
Exine
Intine
Germ pore
Pollen tube
Tube nucleus
Generative nucleus