Answer: Normal cellular aging and senescence.
- A Uncontrolled cancer cell growth and division
- B Normal cellular aging and senescence
- C Faster DNA replication during early development
- D Chromosome condensation before cell division
Correct answer: B. Normal cellular aging and senescence
Explanation: Telomeres shorten with each cell division. When critically short, cells enter senescence or apoptosis. This contributes to aging.
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.