Cell Cycle CHECKPOINTS ✔

what are the checkpoints in the cell cycle?

what are the checkpoints in the cell cycle?

• G1 checkpoint. at G1/S transition

• G2 checkpoint, at G2/M transition

• Spindle checkpoint, at metaphase to anaphase transition.

G1 CHECKPOINT CHECKS FOR:

Are we ready to divide?

• Size.

Is the cell large enough to divide?

• Nutrients.

Does the cell have enough energy/nutrients to divide?

• Molecular signals/Growth factors

Is the cell receiving positive cues (such as growth factors) from neighbours?

• DNA Damage

Is any of the DNA damaged?

G2 CHECKPOINT CHECKS FOR:

How’s our DNA?

• DNA integrity.

Is any of the DNA damaged?

• DNA replication

Was the DNA completely copied during S phase?

M CHECKPOINT CHECKS FOR:

• Spindle attachment:

Did all our chromosomes align in the centre, ready to be pulled apart?