This is a real-world medical entrance exam question, please give the true answer based on the question and selection. Topic name: Metabolism of nucleic acids, Subject name: Biochemistry
[{'content': 'DNA synthesis occurs during which phase of cell cycle \nSelect and explain. \nA. G 1phase, B. M phase, C. S phase, D. G2 phase', 'role': 'user'}, {'content': 'Answer: C \nExplanation: The replication of the DNA genome occurs only at a specified time during the lifespan of the cell. This period is referred to as the synthetic or S phase. This is usually temporally separated from the mitotic, or M phase, by nonsynthetic periods referred to as gap 1 (G1) and gap 2 (G2) phases, occurring before and after the S phase, respectively Harper30e pg: 383', 'role': 'assistant'}]