Animation of a cell undergoing mitosis, the process by which its genetic material is duplicated before the cell divides. At the start of the clip, the cell nucleus is seen with the centrosome above it. The centrosome divides into two (in the prophase stage of mitosis) and moves to opposite sides of the cell. At the same time the genetic material in the nucleus condenses into X-shaped chromosomes. Each centrosome forms a mitotic spindle made of microtubules, which attach to the chromosomes in the centre of the cell in the prometaphase stage. The chromosomes align down the centre of the cell in metaphase, and then each is divided into two identical halves during anaphase. Each daughter chromosome is then pulled towards one centrosome, and a new nuclear membrane forms around each set of chromosomes during telophase. The cell then divides by cytokinesis into two identical cells.