(mī-ō'sĭs )

[Gr. diminution]

A process of two successive cell divisions, producing cells, egg or sperm, that contain half the number of chromosomes (haploid) in somatic cells. When fertilization occurs, the nuclei of the sperm and ovum fuse and produce a zygote with the full chromosome complement (diploid).

SEE: illus. ; chromosome; mitosis; oogenesis .