Answer: Centrosome amplification and defective SAC leading to ongoing mis-segregation.
- A An excess amount of active telomerase enzyme present within the cell
- B Centrosome amplification and defective SAC leading to ongoing mis-segregation
- C The accumulation of point mutations alone, without any other cellular defect
- D Excessive DNA methylation occurring broadly across the entire genome
Correct answer: B. Centrosome amplification and defective SAC leading to ongoing mis-segregation
Explanation: CIN: ongoing chromosomal mis-segregation in cancer cells. Often caused by centrosome amplification (multipolar spindles), defective SAC, or kinetochore attachment errors.
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.