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Both mitosis and meiosis are processes by which cells divide. What this actually involves is the separation of the DNA and other matter within the nucleus of one cell into two cells.
Mitosis is a process which results in two cells that are identical to each other and to the parent cell. The 46 chromosome strand of DNA (23 pairs) in the parent cell is duplicated and then divided, along with the cytoplasm of the parent cell, through the four step process of prophase, metaphase, anaphase, and telophase. Most cells of the body reproduce themselves through the process of mitosis.
Meiosis is a specialized type of cell division that only takes place in the cells in the testes and ovaries. Meiosis division results in two cells that each have half of the chromosomes of the parent cell. The 46 chromosome strand (23 pairs) divides into germ cells that have 23 chromosomes, one from each of the 23 pairs. When germ cells join together in fertilization, the newly created cell then has 46 chromosomes, arranged in 23 newly mated pairs. Division by meiosis involves the same four steps as does mitosis, but the four steps are repeated twice for an eight-stage division process.