centromere. (Harold, 45). During the G2 phase of Interphase, the cell becomes double its mass at birth, the chromosomes begin to shorten and coil, and the centrioles appear, the cell is now ready to enter into mitosis.In the first and longest phase of mitosis, prophase, the chromosomes become visible and the centrioles split in half and then move to opposite sides of the cell. At this point chromosomes have formed into sister chromatids separated by a structure called a centromere. Spindle fibers are barely visible. This phase takes fifty to sixty percent of the time of mitosis. (Biggs, 214) During metaphase, the short second phase of mitosis, the sister chromatids line up along the equator of the cell. Each sister chromatid has its own spindle fiber. Next comes the third phase of mitosis, Anaphase, in which the centromeres break in half, causing each of the daughter chromatids to start to be pulled to different poles of the cell by means of spindle fibers. The spindle fibers pull the daughter chromatids until they reach the poles of the cell. Finally, the last phase of mitosis called Telophase in which the daughter chromatids are fully pulled toward the poles and the nuclear envelope begins to reappear, the cell also begins to cleave, usually in the spot where the chromatids lined up in metaphase. After mitosis is complete, cytokinesis occurs, cytokinesis is the process in which a cells cytoplasm is split into two equal parts, therefore causing the mother cell to split into two daughter cells. In plants, however, cytokinesis is replaced by the placing of a cell plate on the metaphase equatorMitosis is a process that guarantees better cellular work. The two new daughter cells will carry out the same functions and cellular processes as the parent, ensuring that the two cells will carry out twice as much as the original cell. Mitosis often occurs in multicellular animals and plants, not making the organism reproduce, but rather increasin...
