tetrad

[ te-trad ]

/ ˈtɛ træd /

SEE SYNONYMS FOR tetrad ON THESAURUS.COM

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

tetracrotic, tetracyclic, tetracyclic antidepressant, tetracycline, Tetracyn, tetrad, tetradactyl, tetradactylous, tetradrachma, tetradymite, tetradynamous

Dictionary.com UnabridgedBased on the Random House Unabridged Dictionary, © Random House, Inc. 2020

Example sentences from the Web for tetrad

In figure 130 one lagging chromosome shows the dyad nature of the products of the division of the tetrad.
Studies in Spermatogenesis (Part 1 of 2)|Nettie Maria Stevens
There are five axes of symmetry, one tetrad and two pairs of dyad, each perpendicular to a plane of symmetry.
Encyclopaedia Britannica, 11th Edition, Volume 7, Slice 7|Various
They are aborting members of the tetrad, and appear to have been used as food by the other spores.
Ancient Plants|Marie C. Stopes
They are parallel to the edges of the cube, and in the different classes coincide either with tetrad or dyad axes of symmetry.
Encyclopaedia Britannica, 11th Edition, Volume 7, Slice 7|Various

During the tetrad division in the basidium nuclear reduction occurs.
Encyclopaedia Britannica, 11th Edition, Volume 11, Slice 3|Various

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

Collins English Dictionary - Complete & Unabridged 2012 Digital Edition © William Collins Sons & Co. Ltd. 1979, 1986 © HarperCollins Publishers 1998, 2000, 2003, 2005, 2006, 2007, 2009, 2012

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.

单词	tetrad
释义	tetrad [ te-trad ] / ˈtɛ træd / SEE SYNONYMS FOR tetrad ON THESAURUS.COM 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 tetracrotic, tetracyclic, tetracyclic antidepressant, tetracycline, Tetracyn, tetrad, tetradactyl, tetradactylous, tetradrachma, tetradymite, tetradynamous Dictionary.com UnabridgedBased on the Random House Unabridged Dictionary, © Random House, Inc. 2020 Example sentences from the Web for tetrad In figure 130 one lagging chromosome shows the dyad nature of the products of the division of the tetrad. Studies in Spermatogenesis (Part 1 of 2)\|Nettie Maria Stevens There are five axes of symmetry, one tetrad and two pairs of dyad, each perpendicular to a plane of symmetry. Encyclopaedia Britannica, 11th Edition, Volume 7, Slice 7\|Various They are aborting members of the tetrad, and appear to have been used as food by the other spores. Ancient Plants\|Marie C. Stopes They are parallel to the edges of the cube, and in the different classes coincide either with tetrad or dyad axes of symmetry. Encyclopaedia Britannica, 11th Edition, Volume 7, Slice 7\|Various During the tetrad division in the basidium nuclear reduction occurs. Encyclopaedia Britannica, 11th Edition, Volume 11, Slice 3\|Various 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 Collins English Dictionary - Complete & Unabridged 2012 Digital Edition © William Collins Sons & Co. Ltd. 1979, 1986 © HarperCollins Publishers 1998, 2000, 2003, 2005, 2006, 2007, 2009, 2012 Words related to tetrad quadruplicate, quadruple, quaternary, quartette, tetralogy, quaternity, quadrivium, quadruplet, quaternion, quadrumvirate, quadrigeminal, quadripartite, quadrivial, quaternate 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. The American Heritage® Stedman's Medical Dictionary Copyright © 2002, 2001, 1995 by Houghton Mifflin Company. Published by Houghton Mifflin Company. 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. The American Heritage® Science Dictionary Copyright © 2011. Published by Houghton Mifflin Harcourt Publishing Company. All rights reserved.
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tetrad

noun

Origin of tetrad

Words nearby tetrad

Example sentences from the Web for tetrad

British Dictionary definitions for tetrad

noun

Word Origin for tetrad

Words related to tetrad

Medical definitions for tetrad

n.

Scientific definitions for tetrad