Meiosis - histology illustration

Overview of the major events in meiosis. Meiosis, a type of nuclear division, occurs only in reproductive cells and results in a diploid cell (having two sets of chromosomes) giving rise to four haploid cells (having a single set of chromosomes). Each haploid cell can subsequently fuse with a gamete of the opposite sex during sexual reproduction. In this illustration, two pairs of homologous chromosomes enter Meiosis I, which results initially in two daughter nuclei, each with two copies of each chromosome. These two cells then enter Meiosis II, producing four daughter nuclei, each with a single copy of each chromosome.

Illustration courtesy National Center for Biotechnology Information.