|Read about mitosis >>||Read about meiosis >>|
There are two kinds of eukaryotic cell division: mitosis and meiosis (see figure, below right). Mitosis, unlike meiosis, is a duplication process: It produces two genetically identical daughter cells from a single parent cell.
Image derived from a drawing by Saperaud|
You yourself grew from a single embryonic cell to the person you are now through mitosis. Even after growth of the body is complete, mitosis continues, replacing cells lost through everyday wear and tear. The constant replenishment of your skin cells, for example, occurs through mitosis. Mitosis takes place in all parts of your body, keeping your tissues and organs in good working order.
Meiosis, on the other hand, is quite different. It shuffles the genetic deck, generating daughter cells that are distinct from one another and from the original parent cell. Although nearly all the different types of cells in your body can undergo mitosis, meiosis in human beings occurs only in cells that will become either eggs or sperm. So, in humans, mitosis is for growth and maintenance, while meiosis is for sexual reproduction.
Note, however, that meiosis II is very similar to mitosis (in that sister chromatids separate from each other in both) — the only significant difference is that in meiosis II there is a single member from each chromosome pair present, whereas in mitosis both members of each chromosome pair are present.
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