Question

Describe the various steps involved in the sexual reproduction in animals. Draw labelled diagrams to show the fertilisation of an ovum (or egg) by a sperm to form a zygote. ​

Answer 1

The following are the steps involved in sexual reproduction in animals:​

• The male parent produces male gametes called sperms which is a small cell with a long tail called flagellum present for movement.​
• The female parent produces female gametes called ova (or eggs) which is a much bigger cell than the sperm and have a lot of cytoplasm.
• The sperm enters into the ovum (or egg) and fuses with it to form a new cell called 'zygote' by the process called fertilisation. So, the zygote is a fertilised ovum (or fertilised egg).​
• The zygote then divides again and again to form a large number of cells that remains together and ultimately zygote grows and develops to become an embryo and then foetus.

Diagram showing fertilisation of an egg by a sperm to form a zygote.