The two phases meiosis is divided into is Meiosis I and Meiosis II. Because Meiosis is not asexual reproduction is uses sexual reproduction by combining the chromosomes of the mother and father. Since each parent give 23 chromosomes to make the whole 46 a human needs, when the chromosomes come together they create tetrads. these are pairs of replicated chromosomes. There are 2 phases because the first phase separates the tetrads leaving the two sister chromatids. During Meiosis II, the sister chromatids are separated like in Mitosis. Overall, the reason that there are two phases is because the maternal and paternal gametes give replicated chromosomes to the zygote.