bivalent /bīvā″lənt/ [L, bis + valere, to be powerful] , (in genetics) a pair of synapsed homologous chromosomes that are attached to each other by chiasmata during the early first meiotic prophase of gametogenesis. The structure serves as the basis for the tetrads from which gametes are produced during the two meiotic divisions. Also called divalent. −bivalence, n.
