Cell+Cycle+&+Mitosis

**CC&M**
=PROPHASE is the first stage of mitosis. Changes occur in both the cytoplasm and nucleus during prophase. = In the nucleus, the fibers of chromatin coil tighter and become folded, which forms discrete chromosomes and the nucleoli dissapear. Each duplicated chromosome appears as two identical chromatids that are joined together, with a narrow "waist" at the centromere.
 * PROPHASE **

In the cytoplasm, the mitotic spindle begins to form as microtubules grow rapidly out from the centrosomes, and they begin to move away from each other. In late prophase, the nuclear envelope breaks into fragments.

Now that the nuclear envelope is gone, the microtubules emerging from the centrosomes at the ends of the spindle can reach the chromosomes, which are now highly condensed. At the centromere region, each sister chromatid has a protein structure called a kinetochore. Some of the spindle microtubules attatch to these protein structures, and by doing so throwing the chromosomes into an agitated motion. The other spindle microtubules make contact with the microtubules coming from the opposite pole. Forces from protein "motors" associates with spindle microtubules move the chromosomes toward the center of the cell.