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

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

Answer: (D)

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 DNA replication is the process of copying the entire genome to prepare for cell division.
3. Identify that DNA replication occurs specifically during the S phase (Synthesis phase) of interphase, where the cell synthesizes a complete copy of its DNA.
4. Note that the G1 phase is primarily for cell growth and preparation for DNA synthesis, while the G2 phase is for further growth and preparation for mitosis.
5. Recognize that the M phase is when mitosis and cytokinesis occur, involving the separation of duplicated chromosomes, not DNA replication.