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. Loss of basal bodies should lead to loss of all cilia, flagella, and centrioles.

b. Motor proteins such as dynein must have evolved before any of these four kinds of structures.

c. Natural selection for cell motility repeatedly selected for microtubular arrays in circular patterns in the evolution of each of these structures.

d. Cilia and flagella arise from the centrioles.

e. Cilia and flagella coevolved in the same ancestral eukaryotic organism.

d. Cilia and flagella arise from the centrioles.

Explanation:

Centrioles are the pair of cylinders each of which has nine triplets of microtubules. Cilia and flagella are short and long projections extending from the cell surface respectively. Both have two central and nine pairs of peripheral microtubules in their basal body. Basal bodies and centrioles are functionally and structurally similar.

The presence of centrioles in the cells of eukaryotic organisms that produce flagellated or ciliated cells and the ability of both basal bodies and centrioles replicate themselves represent the fact that basal bodies of cilia and flagella is actually derived from the centrioles.