# Mitosis and the cell cycle

## Mitosis

Cells divide when:

• an organism grows
• an organism becomes damaged and needs to produce new cells

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

## The cell cycle

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

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

The cell undergoes a type of cell division called .

In mitosis, two cells called 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:

Length of time in phase =

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