tetrad

tetrad /tet·rad/ (tet´rad) a group of four similar or related entities, as (1) any element or radical having a valence, or combining power, of four; (2) a group of four chromosomal elements formed in the pachytene stage of the first meiotic prophase; (3) a square of cells produced by division into two planes of certain cocci (Sarcina) .

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Fallot's tetrad  tetralogy of Fallot.

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tet·rad (ttrd)

n.

1. A group or set of four.

2. A tetravalent atom, radical, or element.

3. A group of four chromatids formed from each of a pair of homologous chromosomes that split longitudinally during the prophase of meiosis.

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tetrad

[tet′rad]

Etymology: Gk, tetra, four

a group of four chromatids of a synapsed pair of homologous chromosomes during the first meiotic prophase of gametogenesis. The group is formed in preparation for the two meiotic divisions in the maturation of gametes. tetradic, adj.

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tetrad

a group of four similar or related entities, as (1) any element or radical having a valence, or combining power, of four; (2) a group of four chromosomal elements formed in the pachytene stage of the first meiotic prophase; (3) a square of cells produced by division into two planes of certain cocci (sarcina).