Meiosis is a type of cell division that reduces the number of chromosomes in the parent cell by half and produces four gamete cells. This process is essential for sexual reproduction and occurs in all sexually reproducing single-celled and multicellular eukaryotes, including animals, plants, and fungi.
Meiosis starts with a single diploid cell, which contains two sets of chromosomes—one from each parent. The process involves two rounds of division, known as meiosis I and meiosis II, resulting in four haploid cells. Each of these cells has a single set of chromosomes.
During meiosis I, homologous chromosomes pair up and exchange genetic material in a process called crossing over. This increases genetic diversity. The homologous chromosomes are then separated into two different cells. In meiosis II, the sister chromatids of each chromosome are separated, resulting in four genetically unique haploid cells.
This intricate process ensures that each gamete has a unique combination of genes, contributing to genetic diversity in offspring.