In the eukaryotic cell cycle, during which phase is DNA replicated before mitosis begins?

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

Answer: (D)

Verified step by step guidance

1. Understand the phases of the eukaryotic cell cycle, which include interphase (G1, S, G2 phases) and the mitotic phase (prophase, metaphase, anaphase, telophase).
2. Recall that DNA replication occurs during the S phase (Synthesis phase) of interphase, where the cell duplicates its DNA in preparation for mitosis.
3. Recognize that the mitotic phases (prophase, metaphase, telophase) involve the processes of chromosome condensation, alignment, and separation, but not DNA replication.
4. Identify that the S phase occurs before mitosis begins, ensuring that each daughter cell receives an identical set of chromosomes.
5. Conclude that the correct phase for DNA replication before mitosis is the S phase of interphase.