In the eukaryotic cell cycle associated with mitosis, during which phase does DNA replication occur?

• A. Prophase of mitosis
• B. G1 phase of interphase
• C. S phase of interphase
• D. Metaphase of mitosis

Answer: (C)

Verified step by step guidance

1. Understand the phases of the eukaryotic cell cycle, which includes interphase and mitosis. Interphase itself is divided into G1, S, and G2 phases.
2. Recall that DNA replication is the process of copying the entire genome to prepare for cell division, ensuring each daughter cell receives a complete set of chromosomes.
3. Identify that DNA replication does not occur during mitosis phases such as prophase or metaphase, as these phases involve chromosome condensation and alignment, not synthesis.
4. Recognize that the G1 phase is primarily a period of cell growth and preparation for DNA synthesis, but actual replication happens later.
5. Conclude that DNA replication occurs during the S phase (Synthesis phase) of interphase, where the cell duplicates its DNA in preparation for mitosis.