They go through a process called Mitosis. Mitosis is made up of four steps: Prophase, Metaphase, Anaphase, and Telophase. (An easy way to remember them is to remember PMAT) In Prophase, the membrane of the nucleus dissolves and the chromosomes replicate. In Metaphase, the chromosomes line up in the middle of the cells and spindle fibers start to form. Then, in Anaphase, the spindle fibers attach to the chromosomes and pull them apart, towords opposite ends of the cell. In Telophase the nucleus re-form around the two sets of DNA and the cells split in half.
