PATHOLOGY

Detailed explanation-1: -The cell has reached a sufficient size which is monitored by the G1 phase, not G2. So, this is not the main prerequisite for clearance at the G2 checkpoint.

Detailed explanation-2: -The G2 checkpoint bars entry into the mitotic phase if certain conditions are not met. As at the G1 checkpoint, cell size and protein reserves are assessed. However, the most important role of the G2 checkpoint is to ensure that all of the chromosomes have been replicated and that the replicated DNA is not damaged.

Detailed explanation-3: -Abstract. The G2 checkpoint prevents cells from entering mitosis when DNA is damaged, providing an opportunity for repair and stopping the proliferation of damaged cells. Because the G2 checkpoint helps to maintain genomic stability, it is an important focus in understanding the molecular causes of cancer.