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How does mitosis work?

Mitosis is the process by which the nuclear material of a eukaryotic cell divides just prior to cytokinesis or cell division. The first step that occurs after the cell enters the mitotic phase is prophase. During prophase, the nuclear envelope degenerates and the chromatin (DNA) condenses into chromosomes. This helps to protect the DNA in the absence of the nuclear envelope. The centrioles begin to move toward opposite poles of the cell.  


The next step of mitosis is metaphase. During metaphase, the chromosomes, consisting of a pair of identical sister chromatids, line up along the metaphase plate (along the center of the cell). Microtubules (mitotic spindle) extend from the centrioles at opposite poles to the centromeres of the sister chromatids and attach.


During the next phase, anaphase, the connected microtubules pull the sister chromatids of each chromosome to opposite ends of the cell so that every chromosome present in the parent cell is now represented at each end of the cell.


Finally, telophase involves the degeneration of the mitotic spindle and reformation of the nuclear envelope around the recently separated chromatids. The DNA decondenses to its chromatin form and a cleavage furrow (where the cell itself is starting to divide) forms.


After mitosis, cell division is completed through cytokinesis. Both daughter cells are identical to the parent cell in terms of genetic content.

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