Which of the following best describes how chromosomes move toward the poles of the spindle during mitosis?
A)The chromosomes are "reeled in" 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

Question

Quizplus · Accepted Answer

Motor proteins of the kinetochores move the chromosomes along the spindle microtubules. This movement is facilitated by the attachment of spindle microtubules to the kinetochores, specialized protein structures on the chromosomes. This allows the chromosomes to be pulled toward the poles of the spindle as microtubules depolymerize behind them. Non-kinetochore spindle fibers do not play a significant role in chromosome movement. Choice A is incorrect because spindle microtubules do not contract in the manner of muscle fibers. Choice E is incorrect because non-kinetochore spindle fibers do not push chromosomes.

Which of the Following Best Describes How Chromosomes Move Toward