During the eukaryotic cell cycle, during which phase is DNA replicated?

• A. M phase (mitosis)
• B. S phase of interphase
• C. G1 phase of interphase
• D. G2 phase of interphase

Answer: (B)

Verified step by step guidance

1. Understand the phases of the eukaryotic cell cycle: G1 phase, S phase, G2 phase (all part of interphase), and M phase (mitosis).
2. Recall that the cell prepares for division during interphase, which includes growth and DNA replication.
3. Identify that DNA replication specifically occurs during the S phase (Synthesis phase) of interphase, where the entire genome is duplicated.
4. Recognize that G1 phase is primarily for cell growth and normal functions, while G2 phase is for preparing the cell for mitosis, but DNA replication does not occur in these phases.
5. Confirm that M phase is when mitosis and cytokinesis happen, involving chromosome segregation and cell division, not DNA replication.