Prophase is the first phase of mitosis. During this phase, the chromosomes inside the cell's nucleus condense and form tight structures. In fact, the chromosomes become so dense that they appear as curvy, dark lines when viewed under a microscope. Because each chromosome was duplicated during S phase, it now consists of two identical copies called sister chromatids that are attached at a common center point called the centromere.
At the start of metaphase, the microtubules arrange the chromosomes in a line along the equator of the cell, known as the metaphase plate . The centrosomes, on opposite poles of the cell, then prepare to separate the sister chromatids.
After metaphase is complete, the cell enters anaphase. During anaphase, the microtubules attached to the kinetochores contract, which pulls the sister chromatids apart and toward opposite poles of the cell . At this point, each chromatid is considered a separate chromosome.
Finally, once anaphase is complete, the cell enters the last stage of the division process — telophase. During telophase, the newly separated chromosomes reach the mitotic spindle and a nuclear membrane forms around each set of chromosomes, thus creating two separate nuclei inside the same cell
During cytokinesis the cytoplasm then divides to produce two identical cells.
