Meiosis - GCSE Biology Definition

Meiosis is a type of cell division that produces sex cells (gametes), such as sperm and eggs, with half the number of chromosomes found in normal body cells. This process occurs in two stages, known as Meiosis I and Meiosis II. During meiosis, a single cell divides twice to create four unique daughter cells, each containing half the genetic information of the original cell. This reduction in chromosome number is important because it ensures that when a sperm and egg join during fertilisation, the resulting embryo has the correct number of chromosomes. Meiosis also increases genetic diversity through a process called "crossing over," where genetic material is exchanged between chromosomes, creating new combinations of alleles.