The Human Body

Meiosis

Meiosis, process of cell division in which the cell’s genetic information, contained in chromosomes, is mixed and divided into sex cells with half the normal number of chromosomes. The sex cells can later combine to form offspring with the full number of chromosomes. The random sorting of chromosomes during meiosis assures that each new sex cell, and therefore each new offspring, has a unique genetic inheritance.

Meiosis differs from normal cell division, or mitosis, in that it involves two consecutive cell divisions instead of one and the genetic material contained in chromosomes is not copied during the second meiotic division. Whereas mitosis produces identical daughter cells, meiosis randomly mixes the chromosomes, resulting in unique combinations of chromosomes in each daughter cell.