Answer: Halt until its DNA is repaired.
- A Halt until its DNA is repaired
- B Immediately enter mitosis
- C Duplicate its DNA faster
- D Fuse with a neighbouring cell
Correct answer: A. Halt until its DNA is repaired
Explanation: The G1/S checkpoint stops a cell with damaged DNA from replicating until the damage is repaired (or triggers apoptosis if it cannot be).
The cell cycle: G1 (growth and preparation), S (DNA replication, chromosome number stays 2n but DNA content doubles), G2 (final checks before division), and M (mitosis itself) - together, G1+S+G2 make up interphase.
Concept context
Mitosis and meiosis: how cells divide for growth, repair, and reproduction.