Meiosis and Crossing-Over
During the first phase of meiosis I, the cell experiences the
four different phases. Those four phases are: Prophase I, Metaphase I, Anaphase I, and Telophase I. Beginning with a diploid cell. In prophase I, the chromosomes start to replicate and compose into 2 homologous pairs, one from the mother and other father. In metaphase I, the sister chromatids line up with two on each side of the equator cell. In anaphase I, the the 2 homologous pairs start to pull opposite poles of the cell. In telophase I, the homologous pairs separate into 2 daughter cells that contain a pair of sister chromatids each. At the end of meiosis I, the two cells that are presented are haploid. In chapter 2 it states, "Primary functions of meiosis is to reduce the chromosome number from the diploid state to the haploid state" (Marion et al., pg 28, 2017).
During meiosis II, the sister chromatids within the 2 daughter cells start to separate and shape into 4 new haploid gametes. Each dividing cells from into four haploid cells. In chapter 2 it states, "meiosis 1 and meiosis 2 reduce the number of chromosomes by half and ensure that each gamete contains a complete set of chromosomes" (Marion et al., pg 28, 2017). The hypothesis is that crossing over occurs during meiosis to create variation in the DNA sequence in the offspring (Marion et al., pg 28, 2017).
Does this sound right? Meiosis 1 and 2?