tetrad
[ te-trad ]
/ ˈtɛ træd /
noun
a group of four.
the number four.
Cell Biology.
a group of four chromatids formed by synapsis at the beginning of meiosis.
Chemistry.
a tetravalent or quadrivalent element, atom, or group.
Origin of tetrad
1645–55; < Greek
tetrad- (stem of
tetrás) group of four
Words nearby tetrad
Example sentences from the Web for tetrad
British Dictionary definitions for tetrad
tetrad
/ (ˈtɛtræd) /
noun
a group or series of four
the number four
botany
a group of four cells formed by meiosis from one diploid cell
genetics
a four-stranded structure, formed during the pachytene stage of meiosis, consisting of paired homologous chromosomes that have each divided into two chromatids
chem
an element, atom, group, or ion with a valency of four
ecology
a square of 2 × 2 km used in distribution mapping
Word Origin for tetrad
C17: from Greek
tetras, from
tettares four
Medical definitions for tetrad
tetrad
[ tĕt′răd′ ]
n.
A group or set of four.
A tetravalent atom, radical, or element.
A group of four chromatids formed from each of a pair of homologous chromosomes that split longitudinally during the prophase of meiosis.
Scientific definitions for tetrad
tetrad
[ tĕt′răd′ ]
A four-part structure that forms during prophase I of meiosis and consists of two homologous chromosomes, each composed of two identical chromatids. During prophase I of meiosis, one chromosome exchanges corresponding segments of genetic material with the other chromosome in the tetrad in the process called crossing over. See more at meiosis.
A group of four cells, as of spores or pollen grains, formed from a parent cell by meiosis. As part of the process of spermatogenesis, a spermatocyte divides into a tetrad of four spermatids, cells which go on to develop into sperm. See more at spermatogenesis.