Sexual reproduction takes place by the combination of special reproductive cells called ‘sex cells’. Sex cells are of two types: male sex cells and female sex cells (which come from two different parents: a male and a female). The sex cells are commonly known as gametes.
Thus, the cells involved in sexual reproduction are called gametes. Gametes are of two types: male gametes and female gametes. In sexual reproduction, a male gamete fuses with a female gamete to form a new cell called ‘zygote’. This zygote then grows and develops into a new organism in due course of time.
Please note that the sex cells or gametes are also sometimes called germ cells. And there are two types of germ cells: male germ cells and female germ cells. In this chapter we will be mostly using the term ‘gamete’. The students are, however, free to use the term ‘germ cell’ (in place of gamete).