bivalent

bivalent
1. Having a combining power (valence) of 2. SYN: divalent. 2. In cytology, a structure consisting of two paired homologous chromosomes, each split into two sister chromatids, as seen during the pachytene stage of prophase in meiosis. SEE ALSO: tetrad.

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bi·va·lent (')bī-'vā-lənt adj
1 a) DIVALENT
b) having two combining sites <a \bivalent antibody capable of binding to two molecules of an antigen>
2) associated in pairs in synapsis
3) conferring immunity to two diseases or two serotypes <a \bivalent vaccine protecting against hepatitis A and hepatitis B>
bivalent n a pair of synaptic chromosomes

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n.
(in genetics) a structure consisting of homologous chromosomes attached to each other by chiasma during the first division of meiosis.
• bivalent adj.

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bi·va·lent (bi-vaґlənt) 1. having a valence of two; divalent. 2. the structure formed by a pair of homologous chromosomes joined by synapsis along their length during the zygotene and pachytene stages of the first meiotic prophase. After each of the paired chromosomes separates into two sister chromatids during the pachytene, this structure is called a tetrad. 3. effective against two different entities, as diseases or strains of a pathogen.

Medical dictionary. 2011.

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  • bivalent — bivalent, ente [ bivalɑ̃, ɑ̃t ] adj. • 1866; de bi et valent 1 ♦ Chim. Qui a la valence 2. Molécule bivalente (on dit aussidivalent, ente). 2 ♦ Log. Logique bivalente, qui ne considère que deux valeurs de vérité, le vrai et le faux. 3 ♦ Fam. Qui… …   Encyclopédie Universelle

  • bivalent — BIVALÉNT, Ă, bivalenţi, te, adj. (Despre un element sau un radical chimic) Care are valenţa doi. – Din fr. bivalent. Trimis de paula, 21.06.2002. Sursa: DEX 98  BIVALÉNT adj. (chim.) divalent. Trimis de siveco, 05.08.2004. Sursa: Sinonime … …   Dicționar Român

  • Bivalent — may refer to: *Bivalent (chemistry), a molecule formed from two or more atoms bound together as a single unitmolecule *Bivalent (engine), an engine that can use petroleum and renewable energy *Bivalent (genetics), a pair of homologous chromosomes …   Wikipedia

  • Bivalent — ist eine aus Chromosomen gebildete Struktur während der Meiose, siehe Bivalent (Meiose) Siehe auch: Bivalenz Diese Seite ist eine Begriffsklärung zur Unterscheidung mehrerer mit demselben Wort bezeichneter Begri …   Deutsch Wikipedia

  • Bivalent — Biv a*lent, a. [L. bis twice + valens, p. pr. See {Valence}.] (Chem.) Equivalent in combining or displacing power to two atoms of hydrogen; dyad. [1913 Webster] …   The Collaborative International Dictionary of English

  • bivalent — bivalent. См. бивалент. (Источник: «Англо русский толковый словарь генетических терминов». Арефьев В.А., Лисовенко Л.А., Москва: Изд во ВНИРО, 1995 г.) …   Молекулярная биология и генетика. Толковый словарь.

  • Bivalént — (neulat.), zweiwertig …   Kleines Konversations-Lexikon

  • bivalent — 1864, of chemicals, 1899, of chromosomes, from BI (Cf. bi ) + valent, from L. valentem, prp. of valere be worth (see VALIANT (Cf. valiant)) …   Etymology dictionary

  • bivalent — [bi valənt, biv′ələnt, bī bvā′lənt] adj. 1. Chem. DIVALENT: see VALENT 2. Biol. double: said of a chromosome formed by two equivalent chromosomes that lie close together or appear to join completely during meiosis n. a double chromosome; dyad …   English World dictionary

  • Bivalent — Chromosomes homologues Des chromosomes homologues (une paire de chromosomes homologues forment un bivalent) sont des chromosomes appartenant à la même paire, de même taille possédant les mêmes gènes mais pas obligatoirement les mêmes allèles.… …   Wikipédia en Français

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