- 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.
* * *bi·va·lent (')bī-'vā-lənt adj1 a) DIVALENTb) having two combining sites <a \bivalent antibody capable of binding to two molecules of an antigen>2) associated in pairs in synapsis3) 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
* * *n.(in genetics) a structure consisting of homologous chromosomes attached to each other by chiasma during the first division of meiosis.• bivalent adj.
* * *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.