What is "bivalent"

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.

1864, of chemicals, 1899, of chromosomes, from bi- + -valent, from Latin valentem, present participle of valere "be worth" (see valiant).\n

a. 1 (context chemistry English) Having a valence of 2. 2 (context genetics English) Of, or relating to a pair of homologous synapsed chromosomes that occur during meiosis. n. (context genetics English) Any bivalent chromosome.

1. adj. having a valence of two or having two valences [syn: divalent]

2. used of homologous chromosomes associated in pairs in synapsis [syn: double] [ant: multivalent, univalent]

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 operate on two different type of fuel
• Bivalent (genetics), a pair of homologous chromosomes
• Bivalent logic, a classical logic of two values, true and false

See also:
* Bivalent ligand

A bivalent engine is an engine that can use two different types of fuel. Examples are petroleum/ CNG and petroleum/ LPG engines, which are widely available in the European passenger vehicle aftermarket.

A bivalent, sometimes referred to as a tetrad, is the association of a pair of homologous chromosomes physically held together by at least one DNA crossover. This physical attachment allows for alignment and segregation of the homologous chromosomes in the first meiotic division.