Centrioles, cilia, flagella, and basal bodies have remarkably similar structural elements and arrangements. Which of the following hypotheses is most plausible in light of such structural similarities?
A) Cilia and flagella arise from centrioles.
B) Loss of basal bodies should prevent cells from dividing in two.
C) Motor proteins such as dynein must have evolved before any of these four kinds of structure.
D) Cilia and flagella evolved separately in the same ancestral eukaryotic organism.
E) Natural selection for cell motility repeatedly selected for microtubular arrays in circular patterns in the evolution of each of these structures.

Question

Quizplus · Accepted Answer

The fact that centrioles, cilia, flagella, and basal bodies have similar structural elements and arrangements suggest that they are evolutionarily related. Studies have shown that cilia and flagella are derived from centrioles, as both structures contain microtubules arranged in a "9+2" pattern. Basal bodies, which are necessary for the formation of cilia and flagella, are also structurally and functionally similar to centrioles. Therefore, it is most plausible that cilia and flagella arise from centrioles.

Centrioles, Cilia, Flagella, and Basal Bodies Have Remarkably Similar Structural