The main purpose of mitosis is to promote growth and facilitate cell repair while the primary role of meiosis is to produce gametes, which include sperm and eggs. Mitosis and meiosis are both involved in the process of reproduction: these biological functions involve cell division and replication, but perform their tasks in different ways.
Mitosis and meiosis are specialized types of cell division, but take place in different locations. Mitosis occurs only in body cells, or somatic cells, while meiosis takes place in the cells of the testes and ovaries, which are the primary reproductive organs. Mitosis is triggered by the coupling of haploid sperm with a haploid egg; this coupling leads to fertilization. After being fertilized, eggs divide in half, then divide again. This process continues for several subsequent stages of division, and may occur hundreds and thousands of times. This division ultimately produces growth and development of a new offspring. Mitosis also facilitates cell repairs: as cells grow and divide, they are damaged and either repaired through mitosis or regenerated. Meiosis, in contrast, occurs in the reproductive organs. Like mitosis, it occurs in several stages, but ultimately reduces the number of chromosomes in offspring to half their normal numbers. This ensures that offspring have the appropriate number of chromosomes as they begin to develop.