Question

Checkpoints are points between phases of the cell cycle at which a cell determines whether all the requirements necessary for each phase of the cell cycle have been properly satisfied. For example, because a cell with damaged DNA can lead to cancer if it is allowed to divide, a cell with damaged DNA usually arrests the cell cycle until the damage can be repaired. At which phase(s) of the cell cycle would a cell normally check for the integrity of its DNA

Answer 1

The correct answer is - at the G1/S phase and G2/M phase.

Explanation:

The G1/S transition phase or checkpoint is a phase where the cell cycle arrested if during the evaluation of the DNA found damaged or other factors including external factors. Due to this evaluation and inadequate conditions, the cell will not enter the S phase.

The G2/M phase or transition phase is a checkpoint which takes place just before the M phase that ensures that all replicated DNA is not damaged before entering mitosis phase or M phase.

Thus, the correct answer is - at the G1/S phase and G2/M phase.