Answer: Attach spindle microtubules to chromosomes at centromeres.
- A Break double-stranded DNA at specific replication origins
- B Attach spindle microtubules to chromosomes at centromeres
- C Produce ATP via oxidative phosphorylation during division
- D Form the new cell plate during plant cytokinesis
Correct answer: B. Attach spindle microtubules to chromosomes at centromeres
Explanation: Kinetochores are protein complexes on the centromere of each chromatid. Spindle microtubules attach here to pull chromosomes apart.
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.