Which checkpoint checks that the DNA is copied correctly?

Which checkpoint checks that the DNA is copied correctly?

• A. G1 checkpoint
• B. G2 checkpoint
• C. M checkpoint
• D. S checkpoint

Answer: (B)

The checkpoint before mitosis validates the integrity of replicated DNA. After the genome has been copied, the G2 checkpoint scans for any replication errors or DNA damage and ensures replication is complete. If problems are found, the cell cycle is paused to allow repairs; only when the DNA is confirmed intact does the cell proceed to mitosis. That makes it the appropriate stage to check that the DNA has been copied correctly. The G1 checkpoint looks earlier, before replication, assessing readiness and potential damage prior to S phase. The M checkpoint checks proper chromosome alignment and spindle attachment during mitosis. The focus on confirming complete and accurate replication before division is why the G2 checkpoint is the correct choice.

The checkpoint before mitosis validates the integrity of replicated DNA. After the genome has been copied, the G2 checkpoint scans for any replication errors or DNA damage and ensures replication is complete. If problems are found, the cell cycle is paused to allow repairs; only when the DNA is confirmed intact does the cell proceed to mitosis. That makes it the appropriate stage to check that the DNA has been copied correctly. The G1 checkpoint looks earlier, before replication, assessing readiness and potential damage prior to S phase. The M checkpoint checks proper chromosome alignment and spindle attachment during mitosis. The focus on confirming complete and accurate replication before division is why the G2 checkpoint is the correct choice.