Enzyme roles in mitotic cell cycle phases

Steps:

• Identify cell cycle phases: G1 (growth), S (DNA replication), G2 (preparation), M (mitosis).
• Locate DNA ligase: joins DNA fragments during replication in S phase.
• Locate RNA polymerase: transcribes DNA to RNA primarily in G phases (G1/G2) of interphase.
• Match to options: only D places both correctly.

Why D is correct:

• DNA ligase seals Okazaki fragments during S-phase DNA replication; RNA polymerase drives transcription in G phases per interphase gene expression definitions.

Why the others are wrong:

• A: DNA ligase acts in S, not G2; RNA polymerase functions in G phases too, not just S.
• B: DNA ligase acts in S, not G1; RNA polymerase halts in mitosis due to chromatin condensation.
• C: DNA ligase acts in S, not mitosis; RNA polymerase functions in G1/S too, not just G2.

Final answer: D