The Cell Cycle Essay Example | Topics and Well Written Essays - 500 words - 20

The Cell Cycle - Essay Example Meiosis is a form of cell division that results in the formation of haploid gametes. In meiosis I, the homologous chromosomes are separated. The first phase is prophase I where the chromosome condenses and pairs to recombine. The second is metaphase I that involves attachment of chromosomes to the spindle fibers and aligns with the call center. At anaphase I, the chromosomes migrate to opposite poles while spindle fibers shorten. The last phase is telophase I where there is the formation of the nuclear membrane.However, meiosis II involves separation of the chromosomes to form two chromatids. The phases in meiosis II include prophase II, where there is dissolving of the nuclear membrane, condensing of chromosomes and the formation of spindle fibers. In Metaphase II, chromosomes align at the center of attachment of spindle fibers. Anaphase II follows; chromatids migrate to opposite poles while spindle fibers shorten. The last phase is telophase II where there is the formation of the n uclear membrane. Finally, the cytokinesis occurs resulting in the formation of four haploid cells.In prophase I, anaphase I and anaphase II there is crossing over that lead to the formation of four unique chromatids hence increasing genetic variation. Crossing over is vital in the evolution since it brings emergence of species that are more adapted and resistant in the environment. The two-fold cost of sexual reproduction refers to where members must produce both male and female sexes during reproduction.