Editing Prophase (section)

==== Pachytene ====
The third phase of prophase I, pachytene (from the Greek for "thick"), begins at the completion of synapsis.<ref name=":2" />{{rp|98}} [[Chromatin]] has condensed enough that [[chromosome]]s can now be resolved in [[microscopy]].<ref name=":1" /> Structures called recombination nodules form on the [[synaptonemal complex]] of [[Bivalent (genetics)|bivalents]]. These recombination nodules facilitate [[Chromosomal crossover|genetic exchange]] between the non-sister chromatids of the [[synaptonemal complex]] in an event known as [[Chromosomal crossover|crossing-over]] or genetic recombination.<ref name=":2" />{{rp|98}} Multiple recombination events can occur on each bivalent. In humans, an average of 2-3 events occur on each chromosome.<ref name=":4" />{{rp|681}}