What happens during prophase of meiosis?
Meiosis is divided into meiosis I and II , and each have Prophase I and II respectively.
Prophase I ( meiosis I )
During this the homologous chromosomes pair and exchange DNA in a process called homologous recombination. This process is critical for pairing between homologous chromosomes.
The paired and replicated chromosomes are called bivalents or tetrads. They have two chromosomes and four chromatids.
Prophase I is further divided into 5 substages according to the appearance of chromosomes. The stages are - Lepotene, Zygotene, Pachytene, Diplotene and Diakinesis.
Prophase II (meiosis II )
The disappearance of the nucleolii and nuclear envelope is observed . There is shortening and thickening of the chromatids. Centrosomes move to the polar regions and arrange spindle fibres for the second meiotic division.