From Biology-Online Dictionary | Biology-Online Dictionary


noun, plural: tetrads

(1) (cell biology) A group of four closely associated chromatids of a homologous pair formed by synapsis.

(2) (genetics) The four spores of yeast.

(3) (chemistry) A tetravalent atom; a quadrivalent element.

(4) A group consisting of four; the number four.


In cell biology, a tetrad pertains to the structure formed by the synapsis of homologous chromosomes during the prophase I of meiosis.

Word origin: Greek tetras, tetrad-

Synonym: bivalent

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