The process of cell division is prone to errors. It is important that these errors don't get passed on to daughter cells.
- To deal with errors, the cell cycle has checkpoints at certain stages.
- They make sure that the requirements for the next stage are fulfilled.
- If problems are found, then the cell cycle is halted and programmed cell death (or apoptosis) occurs.
There are three checkpoints:
- A checkpoint at the end of the G1 phase (the G1 checkpoint)
- A checkpoint at end of the S phase (the G2 checkpoint)
- A checkpoint at the end of mitosis (the M checkpoint)