An advantage is that the sorting and recombination of genes in meiosis result in a greater variety of possible gene combinations than could result from mitosis.

One disadvantage of meiosis is that it requires two organisms to reproduce, which takes more time and energy. In humans, there would be 46 chromosomes in the beginning, and 23 in the end. During prophase I, differences from mitosis begin to appear. As in mitosis, the cell grows during G 1 1 phase, copies all of its chromosomes during S phase, and prepares for division during G 2 2 phase. The daughter cells are genetically different from one another. Meiosis I Before entering meiosis I, a cell must first go through interphase. This results in four haploid daughter cells. In metaphase II, the chromosomes line up in the center of each cell, similar to metaphase I.Īfter metaphase II, the cells enter anaphase II where the paired chromosomes separate, similar to anaphase Iįinally, the cells enter telophase II and Cytokinesis. In prophase II, the cells’ chromosomes become visible, but they do not form tetrads like they did in prophase I. View meiosisbook (1).pdf from BIOL 2110 at San Juan College. Cytokinesis comes after telophase I forming two new cells.Īfter meiosis I is complete, the resulting two daughter cells enter meiosis II. During telophase I, a nuclear membrane forms around the clusters of chromosomes. Then, the spindle fibers pull each homologous chromosome pair towards the opposite sides of the cell during anaphase I.Īfter anaphase I the cell goes into telophase I. During metaphase I the paired homologous chromosomes line up across the middle of the cell. View meiosisbook (1).pdf from BIOL 2110 at San Juan College. This produces new combinations of alleles in the cell.Īfter prophase I ends, metaphase I begins. The chromosomes also cross over and exchange the crossed sections. In prophase I, each replicated chromosome pairs with its homologous chromosome. After the chromosomes in the cell replicate during interphase, the cell enters prophase I.

Meiosis flipbook pdf