Bivalent chromosomes are pairs of homologous chromosomes that come together during cell division and recombination. Synonyms for bivalent chromosomes include tetrad, synapsed chromosome, or paired chromosomes. The term tetrad is used to describe the four chromatids that make up a bivalent chromosome during meiosis. A synapsed chromosome refers to homologous chromosomes that are paired and joined together by a synaptonemal complex. Paired chromosomes simply refers to the existence of a homologous partner chromosome. These synonyms are useful for describing the complex mechanisms of meiosis and how chromosomes pair up to ensure genetic diversity in offspring.