The first stage in the first meiotic division of meiosis. This stage is characterized by having five sub-stages namely leptotene, zygotene, pachytene, diplotene and diakinesis. It highlights the exchange of DNA between homologous chromosomes via a process called homologous recombination and the cross-over at chiasma(ta) between non-sister chromatids. Thus, this stage is important to increase genetic variation. This stage then ends with the disintegration of the nucleolus and the nuclear membrane.