Chiasmata appear as evidence that crossing over has occurred. Neither synapsis nor crossing over occurs. Individual chromosomes line up on the metaphase plate. I separates pairs of chromosomes. Centromeres do not divide and sister chromatids of each chromosome move together to the pole of the cell.
Mitosis separates sister chromatids of individual chromosomes.
Centromeres divide and sister chromatids move to opposite poles of the cell. V. Sexual life cycles produce genetic variation among offspring Meiosis and fertilization are the primary sources of genetic variation in sexually reproducing organisms. A. Independent Assortment of Chromosomes At Metaphase I, each homologous pair of chromosomes aligns on the metaphase plate. Each pair consists of one maternal and one paternal chromosome. A gamete produced by meiosis contains just one of all the possible combinations of maternal and paternal chromosomes.