Pachytene, also known as pachynema, comes from the Greek meaning of “thick thread” because by this stage the homologous chromosomes are synapsed, or have been fully zipped up and are connected from end to end by the synaptonemal complex. This fully synapsed unit of chromosomes is referred to as a tetrad.

What does Diplotene mean?

: a stage of meiotic prophase which follows the pachytene and during which the paired homologous chromosomes begin to separate and chiasmata become visible.

What is zygotene stage?

The zygotene is the stage of prophase I that follows after leptotene and precedes pachytene. Prior to zygotene, the chromosomes start to condense into long strands inside the nucleus and the chromosomes appear as threadlike. Zygotene is that phase wherein the homologous chromosomes pair or come together in synapse.