[Campbell Biology P.289] Based on Figure 12.8 and the text, which statement accurately descr... | Practice Question
Based on Figure 12.8 and the text, which statement accurately describes a type of microtubule in the mitotic spindle at metaphase?
A: Kinetochore microtubules are responsible for pushing the poles apart, extending from the centrosomes but not attaching to chromosomes.
B: Nonkinetochore microtubules elongate, overlap, and interact with those from the opposite pole, contributing to spindle elongation.
C: Aster microtubules extend from kinetochores to the cell periphery, pulling chromosomes towards the poles.
D: All microtubules in the spindle attach to the kinetochores of chromosomes to align them at the metaphase plate.
Explanation
The text states: 'Meanwhile, microtubules that do not attach to kinetochores have been elongating, and by metaphase they overlap and interact with other nonkinetochore microtubules from the opposite pole of the spindle.' Figure 12.8 also labels 'Overlapping nonkinetochore microtubules'.