​Explain why cells divide by mitosis. Give at least one example of cells that need to undergo mitotic division.

​In multicelled organisms, mitosis and cytoplasmic division are the basis of body formation and increases in size during development: Continuing mitotic divisions of embryonic cells as they differentiate produce tissues and body parts of the embryo. Juvenile development into the adult form also occurs by mitosis, as do ongoing replacements of damaged or dead cells. Scrape your knee, and mitotically dividing cells in your skin repair the wound. Skin cells and many other types of body cells are continually replaced by mitosis.