Answer: Proportion of cells in mitosis (used in cancer diagnosis).
- A The overall physical size of individual dividing cells
- B Proportion of cells in mitosis (used in cancer diagnosis)
- C The rate of DNA synthesis occurring during interphase
- D The total number of chromosomes present per cell
Correct answer: B. Proportion of cells in mitosis (used in cancer diagnosis)
Explanation: Mitotic index = (cells in mitosis) / (total cells). High mitotic index indicates rapid cell division. Used in cancer staging.
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.