This is a real-world medical entrance exam question, please give the true answer based on the question and selection. Topic name: Replication, Subject name: Biochemistry
Chromosomes are formed during which phase of cell cycle 
Select and explain. 
A. G1, B. S, C. G2, D. M
D: M
Answer: D: M 
Explanation: Though the DNA is synthesized during the S phase of cell cycle, but the condensation of chromatin fibers into Chromosomes happens during metaphase of Mitosis phase (M) of cell cycle. Hence, if question ask about which phase of cell cycle for DNA synthesis, the answer is S phase. If asked about the chromosome formation, answer is M phase.