Following steps are involved in the process of sexual reproduction in animal:

(i) In animal, male parent produce male gametes called sperms. Millions of sperms are produced by testes (male gonad). The sperm is very small in size and has a head, a middle piece and a tail.

(ii) The female parent produces female gamete called ova (eggs) which is much bigger cell than the sperm, having a lot of cytoplasm. Like a sperm, an egg is also a single cell.

(iii) The next step is fertilisation. In this step, sperm enters the ovum and fuses with it to form a new cell called zygote. The zygote is the beginning of a new individual.

(iv) In this step, zygote begins to develop into an embryo. The zygote divides repeatedly to form a large number of cells and ultimately the zygote grows and develops to form a baby.