Pachytene is the 3rd phase of meiosis prophase-1 (a five-stage process). It is characterized by the appearance of recombination nodules, the region at which crossing over takes place between non-sister chromatids of the homologous chromosomes. Nodules comprise a multienzyme complex known as recombinase.

How will you define pachytene?

: the stage of meiotic prophase that immediately follows the zygotene and that is characterized by paired chromosomes thickened and visibly divided into chromatids and by the occurrence of crossing-over.

What is the function of pachytene?

The pachytene checkpoint prevents meiotic nuclear division in cells that fail to complete meiotic recombination and chromosome synapsis. This control mechanism prevents chromosome missegregation that would lead to the production of aneuploid gametes.