Question

Once the cell passes the G1 checkpoint and enters S phase:

• A. the cell cycle is completed bypassing the M phase.
• B. the cell cycle is completed bypassing the G2 checkpoint.
• C. completion of cell cycle will depend on G2 checkpoint.
• D. the cell will next enter M phase bypassing the G2 checkpoint.

Hint:

G1 Checkpoint = Commitment to divide. G2 Checkpoint = Commitment to Mitosis.

Answer 1

The Correct Option is C

Step 1: Concept
The cell cycle has multiple checkpoints (G1, G2, and M) that ensure conditions are right for the next stage.

Step 2: Meaning
Passing one checkpoint does not mean others are ignored; it is a sequential verification process.

Step 3: Analysis
The G1 checkpoint is the "Restriction Point." Once passed, the cell commits to DNA replication in S phase. However, before it can enter Mitosis (M phase), it must pass the G2 checkpoint, which verifies that DNA replication is complete and undamaged.

Step 4: Conclusion
The cycle cannot be completed without successfully navigating the G2 checkpoint after S phase. Final Answer: (C)