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.
QUIZZES
LEARN THE SPANISH WORDS FOR THESE COMMON ANIMALS!
Are you learning Spanish? Or do you just have an interest in foreign languages? Either way, this quiz on Spanish words for animals is for you.
Question 1 of 13
How do you say “cat” 🐈 in Spanish?
Origin of tetrad
1645–55; <Greek tetrad- (stem of tetrás) group of four
Words nearby tetrad
Dictionary.com Unabridged
Based on the Random House Unabridged Dictionary, © Random House, Inc. 2021
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
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.
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.