[Campbell Biology P.290] According to the experiment conducted by Gary Borisy and colleagues... | Practice Question

According to the experiment conducted by Gary Borisy and colleagues Figure 12.9 , what was the primary conclusion regarding kinetochore microtubule shortening during anaphase in the studied cell type?

  • A: Kinetochore microtubules shorten primarily at their spindle pole ends.
  • B: Kinetochore microtubules shorten primarily at their kinetochore ends.
  • C: Kinetochore microtubules shorten uniformly along their entire length.
  • D: Kinetochore microtubules lengthen during anaphase due to tubulin addition.

Explanation

The Borisy et al. experiment involved marking kinetochore microtubules with a non-fluorescent region. As anaphase proceeded, the microtubule segments on the kinetochore side of the mark shortened, while those on the spindle pole side stayed the same length. This led to the conclusion that kinetochore microtubules shorten by depolymerizing at their kinetochore ends.