How does meiosis lead to genetic variation?
At the beginning of meiosis (prophase I), homologous chromosomes exchange segments of DNA. This is known as crossing over, and is unique to this phase of meiosis. Meiosis is the type of cell division that produces gametes. Meiosis involves two cell divisions and produces four haploid cells. Sexual reproduction has the potential to produce tremendous genetic variation in offspring. This is due in part to crossing over during meiosis.