Cells divide in a series of stages called the cell cycle. During the cell cycle the genetic material is doubled and then divided into two identical cells.
In the first stage the cell grows and increases the number of sub-cellular structures such as ribosomes and mitochondria. The DNA replicates to form two copies of each chromosome.
In the second stage, mitosis, one set of chromosomes is pulled to each end of the cell and the nucleus divides. In the final stage the cytoplasm and cell membranes divide to form two identical cells.
Mitosis is important in the growth and development of multicellular organisms, because it makes new cells that are genetically identical to the parent cell. You are expected to recognise situations where mitosis is happening, such as a child growing, or a wound healing as new skin cells are made.
