Which of the following best describes how chromosomes move toward the poles of the spindle during mitosis?
A) The chromosomes are ʺreeled inʺ by the contraction of spindle microtubules.
B) Motor proteins of the kinetochores move the chromosomes along the spindle microtubules.
C) Non-kinetochore spindle fibers serve to push chromosomes in the direction of the poles.
D) both A and B
E) A, B, and C
Answer: B