tetrad (suomeksi)

Määritelmät:

A group of four things.
(lb, en, cartography) A unit of land area of two by two (that is, four) square kilometres.
(lb, en, chemistry) A tetravalent atom or radical.
(lb, en, biology) Two pairs of sister chromatids (a dyad pair) aligned in a certain way and often on the equatorial plane during the meiosis process.
(lb, en, biology) A group of four haploid and immature pollen grains in tetrahedral fashion produced by meiotic microsporogenesis.