Explain the process of gamete transfer.

Explanation

After formation of male and female gamete, they are brought together to facilitate the process of fertilization.
In majority of organisms, the male gamete is motile and female gamete is non motile.
Male gamete requires medium to travel.
In algae, bryophyta and pteridophyte, male gamete, travels through water medium.
A large number of male gametes, however, fails to reach the female gamete.
To compensate this loss of male gamete, during their travel the number of male gametes produced is several times than the number of female gametes.
In Angiosperms pollen grains are the carriers of male gametes and ovule has egg cell.
Pollen grain are produced in anthers and transferred to stigma through a process called pollination.
This procss involves external agents like water, air, insects, birds, etc.
Pollen grains germinate on stigma and the pollen tube carrying male gametes reaches ovule and discharges two male gamete near the egg cell.
In bisexual animals, since male and female gametes are formed in different individual, the organism must evolve a special mechanism for gamete transfer.
This is the prerequisite for fertilization.