Mitosis

Mitosis is the process by which body cells divide to make new cells.  Each daughter cells will be identical to the parent cell.

Stages of Mitosis

Interphase- Before S Phase

            The cell is performing its day-to-day activities (such as being a liver cell or a stomach cell).  The cell is also preparing for mitosis, or cell division.  Chromosomes will be found as long threads called chromatin.

Interphase- After S Phase

            Chromosomes, which are made of DNA, undergo a process called replication, which creates two copies of the genetic material. The S in S-Phase stands for synthesis, the process by which DNA copies itself.  The cell is now ready to begin mitosis.

Mitosis- Prophase

            Chromatin in the nucleus begins to condense and X-shaped chromosomes appear.  The nuclear membrane dissolves so that chromosomes can move around the cell.  The centrioles move to opposite ends of the cell and spindle fibers start to appear.

Mitosis- Metaphase

            The spindle apparatus fully develops.  Spindle fibers line the chromosomes up in the middle of the cell.   When metaphase is complete, there will be a neat row of chromosomes at the equator of the cell.

Mitosis- Anaphase

            Spindle fibers shrink to pull the chromosomes apart.  One sister chromatid moves to each pole of the cell.  Both sides of the cell have a full copy of the genetic material.

Mitosis- Telophase

            A complete set of chromosomes can be found at each pole of the cell.  The chromosomes uncoil into chromatin.  The cell begins to divide into two daughter cells. The nuclear membrane begins to reappear.