Cell Cycle: Checkpoints Monitored by a Cell

What are the checkpoints monitored by a cell before proceeding through the cell cycle?

a) G1 checkpoint b) S checkpoint c) G2 checkpoint d) All of the above

Final answer: d) All of the above

Answer:

The checkpoints monitored by a cell before it can proceed through the cell cycle are the G1, S, and G2 checkpoints. All of these are monitored, hence the correct answer is d) All of the above.

The checkpoints monitored by a cell before proceeding through the cell cycle are: the G1 checkpoint, S checkpoint, and G2 checkpoint. Therefore, the correct answer to which checkpoints are monitored is d) All of the above.

The G1 checkpoint assesses whether the cell is large enough to divide and if it's not, the cell enters the resting period (Go).

The S checkpoint ensures that DNA has been replicated properly.

The G2 checkpoint verifies proper chromosome duplication before mitosis.

The M checkpoint ensures all chromosomes are properly aligned and attached to spindle fibers.

External forces have the greatest influence on the G1 checkpoint because growth factor proteins and external signals trigger the decision for a cell to divide. Internal molecular signals like cyclins and cyclin-dependent kinases regulate the cell cycle transitions at these checkpoints.