Answer: One kinetochore is attached to microtubules from BOTH poles, risking lagging chromosomes in anaphase.
- A It physically prevents the completion of DNA replication occurring at the start of every single S phase cycle
- B One kinetochore is attached to microtubules from BOTH poles, risking lagging chromosomes in anaphase
- C It physically blocks formation of the mitotic spindle by sequestering free tubulin subunits in the cytoplasm
- D It causes cytokinesis to begin prematurely before anaphase triggering furrow ingression while chromosomes are still moving
Correct answer: B. One kinetochore is attached to microtubules from BOTH poles, risking lagging chromosomes in anaphase
Explanation: Merotelic attachment: one kinetochore attached to both spindle poles. Not detected by SAC. Can lead to lagging chromosomes and aneuploidy. Corrected by Aurora B kinase.
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.