The male gametes are called as?

Complete the crossword puzzle:

Across
1. The process of the fusion of the gametes.
6. The type of fertilisation in hen.
7. The term used for bulges observed on the sides of the body of Hydra.
8. Eggs are produced here.

Down
2. Sperms are produced in these male reproductive organs.
3. Another term for in vitro fertilisation.
4. These animals lay eggs.
5. A type of fission in Amoeba.