Gametes - GCSE Biology Definition

Gametes are special cells used in sexual reproduction to create new life. In humans and many other animals, there are two types of gametes: sperm and egg cells. Sperm cells, which are usually smaller and mobile, are produced by males. Egg cells, which are larger and stationary, are produced by females. Both types of gametes have half the number of chromosomes compared to normal body cells, which means they are haploid. When a sperm and an egg cell join together during fertilisation, they combine their genetic material to form a complete set of chromosomes, creating a diploid fertilised egg called a zygote. This is the first step in developing a new organism.