Mitosis

=The Cell Cycle and Mitosis= > =Interphase: The cell is engaged in metabolic activity and performing its prepare for mitosis (the next four phases that lead up to and include nuclear division). Chromosomes are not clearly discerned in the nucleus, although a dark spot called the nucleolus may be visible. The cell may contain a pair of centrioles (or microtubule organizing centers in plants) both of which are organizational sites for microtubules. Prophase: Chromatin in the nucleus begins to condense and becomes visible in the light microscope as chromosomes. The nucleolus disappears. Centrioles begin moving to opposite ends of the cell and fibers extend from the centromeres. Some fibers cross the cell to form the mitotic spindle. Prophase is the second phase of mitosis. The copy is now visible and a spindle is beginning to form. Metaphase: Chromatic pairs are lined up in the center of the cell.Tension applied by the spindle fibers aligns all chromosomes in one plane at the center of the cell. Anaphase: Sister chromosomes separate, moving to one side of cell. Each chromosome tightly wrap around each other. Once the chromatids are on each side ,they seperate.Motion results from a combination of kinetochore movement along the spindle microtubules and through the physical interaction of polar microtubules. =
 * = The Cell Cycle and Mitosis =
 * =Telophase:Chromatids arrive at opposite poles of cell, and new membranes form around the daughter nuclei. The chromosomes disperse and are no longer visible under the light microscope. The spindle fibers disperse, and cytokinesis or the partitioning of the cell may also begin during this stage. =