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.
Answer: A
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