Mitosis and the cell cycle

Mitosis

Cells divide when:

  • an organism grows
  • an organism becomes damaged and needs to produce new cells for repair
  • organisms like bacteria reproduce asexually

It is essential that any new cells produced contain genetic information that is identical to the parent cell.

A growing and dividing cell goes through a series of stages called the cell cycle.

The first stages of the cell cycle involve cell growth, then synthesis of DNA. The single strand of DNA that makes up each chromosome produces an exact copy of itself. After this a period of further growth occurs and the DNA is checked for errors. Mitosis occurs after this checking has been completed. Finally the cytoplasm of the cell separates and two cells are formed.

The first stages of the cell cycle involve cell growth, then synthesis of DNA. The single strand of DNA that makes up each chromosome produces an exact copy of itself.Mitosis is a part of the cell cycle

The cell undergoes a type of cell division called mitosis. In mitosis, two cells called daughter cells are produced, each identical to the parent cell.

When looking at cells with a microscope, the length of different stages of the cell cycle can be estimated using the formula:

\text{Length of time in phase}=

\frac{\text{observed number of cells at that stage}}{\text{total number of cells observed}}\times\text{total length of time of cell cycle}