Question

Which of the following statements regarding cilia is not correct?

• A. Cilia contain an outer of nine doublet microtubules surrounding two single microtubules.
• B. The organized beating of cilia is controlled by fluxes of Ca${}^{2+}$ across the membrane.
• C. Cilia are hair-like cellular appendages.
• D. Microtubules of cilia are composed of tubulin.

Answer 1

The correct option is B The organized beating of cilia is controlled by fluxes of Ca${}^{2+}$ across the membrane.

Cilium is an organelle found in eukaryotic cells and are hair-like appendages. Inside cilia, is a microtubule-based cytoskeleton called the axoneme. The axoneme of cilia has a ring of nine outer microtubule doublets and two central microtubule singlets in addition to the nine outer doublets, called 9+2 axoneme.
The organized beating of cilia, however, are produced by controlled sliding of outer doublet microtubules.