Questions: 3. At which of the following checkpoints is the DNA checked for damage and, if damage is present, the cell is placed in G0 phase? a. M c. G2 b. G1 d. None of these are correct. 4. Where is the checkpoint that assesses the DNA for damage? a. G1 c. G2 b. S d. M 5. Which of the following act as the brakes of the cell cycle and prevent cells from dividing too quickly? a. oncogenes b. proto-oncogenes c. cyclins d. tumor suppressor genes

At which of the following checkpoints is the DNA checked for damage and, if damage is present, the cell is placed in \(G_0\) phase? The answer is b: \(G_1\). Explanation: The \(G_1\) checkpoint, also known as the restriction point, is where the cell checks for DNA damage. If damage is detected, the cell can be directed to enter the \(G_0\) phase, a resting state where it does not divide.

Where is the checkpoint that assesses the DNA for damage? The answer is a: \(G_1\). Explanation: The \(G_1\) checkpoint is responsible for assessing DNA for damage before the cell proceeds to the S phase, where DNA replication occurs. This ensures that any damage is repaired before replication.

Which of the following act as the brakes of the cell cycle and prevent cells from dividing too quickly? The answer is d: tumor suppressor genes. Explanation: Tumor suppressor genes act as the brakes of the cell cycle by inhibiting cell division and promoting repair of damaged DNA. They help prevent uncontrolled cell proliferation, which can lead to cancer. Oncogenes and proto-oncogenes, on the other hand, promote cell division, while cyclins regulate the cell cycle but do not act as brakes.