Answer: Aurora B kinase.
- A CDK1
- B Aurora B kinase
- C Polo-like kinase 1
- D ATM kinase
Correct answer: B. Aurora B kinase
Explanation: Aurora B kinase phosphorylates histone H3 at Ser10 during mitosis. This is a widely used marker for cells in mitosis in immunofluorescence.
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.