Interpreting post-metaphase mitotic distances

Steps:

• In anaphase, sister chromatids separate and move toward opposite spindle poles while poles diverge.
• Distance from centromeres to spindle poles decreases as chromosomes approach the poles.
• Distance between sister chromatids increases rapidly due to separation.
• Distance between spindle poles increases steadily as the spindle elongates.
• Graph curves likely show: decreasing (centromere-pole), sharp increase (sister separation), gradual increase (pole distance).

Why A is correct:

• Assigns decreasing curve 1 to centromere-pole distance, matching anaphase definition where chromosomes migrate poleward, reducing this gap.

Why the others are wrong:

• B: Swaps sister separation to curve 1 (decreasing), contradicting chromatid divergence.
• C: Incomplete option, lacks valid assignment.
• D: Assigns pole distance to curve 1 (decreasing), ignoring spindle elongation.

Final answer: A