Mitosis Graph Axes: Spindle Poles vs. Chromatid Separation

Steps:

• Recall that in mitosis graphs, X-axis often tracks spindle pole elongation during anaphase.
• Note Y-axis typically measures separation of structures pulled by spindle fibers.
• Match choices to standard measurements: poles for overall apparatus length, chromatids for separation dynamics.
• Eliminate mismatches by verifying against cell division mechanics.

Why C is correct:

• In anaphase, spindle pole distance (X) increases via microtubule sliding, while sister chromatid distance (Y) increases as kinetochores pull them apart, per microtubule motor protein action.

Why the others are wrong:

• A: Centromeres are fixed points on chromatids; their distance doesn't independently vary like chromatid separation.
• B: Distance from poles (Y) measures single fiber length, not paired structure separation.
• D: Distance from poles (X) confuses pole separation with individual fiber extension.

Final answer: C