Antonyms for Multivalent (opposite meaning)
WordNet sense 1 (used of homologous chromosomes associated in pairs in synapsis):
bivalentWordNet sense 2 (used of a chromosome that is not paired or united with its homologous chromosome during synapsis):
univalentWordNet sense 3 (having a valence of 1):
monovalentFrom the ODE community, based on WordNetadd/edit