Adjacent microtubule doublets in cilia and flagella produce a bending movement because
A) tubulin is contracting on one side of the microtubules.
B) dynein is contracting on one side of the microtubules.
C) kinesin is contracting on one side of the microtubules.
D) nexin links between microtubule doublets convert a sliding movement into a bending movement.

Question

Quizplus · Accepted Answer

The bending movement in cilia and flagella is produced by the action of nexin links between microtubule doublets. These links convert the sliding movement between adjacent doublets, caused by the action of dynein molecules, into a bending movement of the whole structure. Neither tubulin nor kinesin are directly involved in producing the bending movement.

Adjacent Microtubule Doublets in Cilia and Flagella Produce a Bending