Uncontrolled Cell Division (Cambridge (CIE) O Level Biology): Revision Note

Cancer

• Cells in the body divide by mitosis to produce more cells - this is essential for growth and to repair damaged cells

  • For example, the cells of the intestines are constantly dividing to replace those that are shed as food moves through the digestive system

• Mitosis is just one part of the cell cycle which is regulated by many different genes to ensure that cells divide only when they need to and stop when required

• Cancer is caused as a result of mutations in the DNA of cells that lead to uncontrolled cell growth and division - this can result in the formation of a tumour (a mass of cells)

  • Usually, tumours form as a result of loss of control of the cell cycle