Mitosis

The first and longest stage of Mitosis is Prophase. During Prophase, the chromosomes become visible. The centrioles, two tiny structures located in the cytoplasm near the nuclear envelope, separate and take up positions on opposite sides of the nucleus. The centrioles lie in a region called the controsome that helps to organize the spindle, a fanlike microtubule structure that helps separate the chromosomes. During Prophase, condensed chromosomes become attached to fibers in the spidle at a point near a centromere of each chromatid. Plant cells do not have centrioles, yet they still organize their mitotic spindles from centrosomes. Near the end of Prophase, the chromosomes coil more tightly, the nucleolus disappears, and the nuclear envelope breaks down.
The next stage of Mitosis is Metaphase, often the shortest, only lasting a few minutes. During Metaphase, the chromosomes line up along the center, or equator of the cell, the cell plate in plant cells. Microtubules connect the centromere of each chromosome to the poles of the spindle.
Next in Mitosis is Anaphase, the third phase. During this stage, the centromeres that join the sister chromatids separate, allowing the sister chromatids to separate themselves and become individual chromosomes. The chromosomes continue to move until they have separated into two groups near the poles of the spindle. During this, the spindle fibers draw the chromosomes towards the poles while simultaneously elongating the cell and pushing it gradually apart. Anaphase ends when the chromosomes stop moving.
Finally comes the fourth and last phase of Mitosis, Telophase. In Telophase, the chromosomes, which had been distinct and condensed, begin to disperse into a tangle of dense material, and a nuclear envelope re-forms around each cluster of chromosomes. The spindle fibers begin to break apart, and a nucleolus becomes visible in each of these newly formed daughter nuclei. This ends the process of Mitosis, but cell division as a whole, the M Phase, is not complete.

As I have said, the process of Mitosis may be complete, but there is still one part left in the M Phase: Cytokinesis. Click it, and carry on to our final page.