Meiosis, also known as reduction division, consists of two successive cell divisions in diploid cells. The two cell divisions are similar to mitosis, but differ in that the chromosomes are duplicated only once, not twice. The end result of meiosis is...

Nondisjunction is the failure of two members of a homologous pair of chromosomes to separate during meiosis. It gives rise to gametes with a chromosomal content that is different from the norm. The consequences of this are usually quite severe, and a...

Tetrads, the four haploid cell products of a single meiotic division, can be used to study the behavior of chromosomes and genes during meiosis. This kind of analysis is only possible in haploid organisms, such as some fungi or single-celled algae, in...

A special division of the cell in organisms that reproduce sexually. The nucleus of the cell divides to produce four daughter nuclei, each with half the complement of the parent nucleus. The female sex chromosomes each give rise to a sex cell (egg)...

In biology, meiosis (pronounced mi-o-sis or me-o-sis) is the process by which one diploid eukaryotic cell divides to generate four haploid cells often called gametes. The word "meiosis" comes from the Greek meioun, meaning "to make smaller," since it...

Venerable theories don't get a Holliday [sic ] pass Thousands of geneticists owe their livelihoods to meiotic recombination, that diversity-promoting process during egg and sperm development when homologous chromosomes from Mom and Dad swap pieces. But recombination is so dauntingly complex that only...

Meiosis is often described as a special case of cell division since it differs from mitosis in having two nuclear divisions without an intervening S-phase. It will be of great interest to uncover what molecular mechanisms underlie these special features of meiosis. We previously...