Cells divide using mitosis. The stages of mitosis are: interphase, prophase, metaphase, anaphase and telophase. In interphase the DNA is loose in the nucleus and is copied to result in 2 identical copies of all chromosomes. During prophase the DNA condenses and become X-shaped structures which are what we think of when we think of chromosomes because they can be seen down a microscope. Each chromosome is formed of 2 sister chromatids which are identical. At the end of prophase the nuclear membrane dissolves and the mitotic spindle move to opposite poles of the cell. In metaphase the chromosomes line up along the equator of the cell. The centrioles are at opposite poles of the cell and the mitotic spindle fibres extend from them to attach to each of the sister chromatids. In anaphase the sister chromatids are pulled apart by the mitotic spindle which pulls one sister chromatid to one pole and the other sister chromatid to the opposite pole. In telophase there is now a full set of chromosomes at each pole, a new membrane forms around each set to form 2 new nuclei. Cytokinesis then occurs where the cell membrane pinches in to divide into 2 new daughter cells.