Meiosis I Prophase I stages are: - Leptotene: Chromosomes condense. - Zygotene: Homologous chromosomes begin to pair up (synapsis) with the formation of the synaptonemal complex. - Pachytene: Synapsis is complete, and crossing over (chiasmata formation) occurs. - Diplotene: Homologous chromosomes begin to separate, but remain attached at chiasmata. The synaptonemal complex disassembles. - Diakinesis: Chromosomes condense further, and chiasmata are visible.