During which phase does recombination occur in meiosis?

Recombination occurs during Prophase I of meiosis, which is a crucial phase where homologous chromosomes pair up and exchange genetic material through a process called crossing over. This pairing forms tetrads, consisting of four chromatids, and during this close association, chromatids from homologous chromosomes can break and rejoin, leading to genetic diversity in the resulting gametes.

This genetic shuffling is significant for the evolution of species, as it increases variability in traits within a population. The recombination process essentially mixes maternal and paternal genetic material, which is an essential mechanism contributing to the diversity of alleles in sexually reproducing organisms.

In contrast, Metaphase I is characterized by the alignment of tetrads at the cell's equatorial plane, Anaphase I involves the separation of the homologous chromosomes moving to opposite poles, and Telophase I is where the cell begins to divide into two haploid cells. None of these phases are involved in the actual process of crossing over, which is specifically tied to Prophase I.