Question

Which of the following show (9+0) arrangement?
A. Centriole and basal bodies
B. Cilia
C. Centriole
D. Cilia flagella

Answer 1

Hint: The cytoskeleton is the arrangement that supports the body of an organism and also involves in the movement of the organisms. The cilia and flagella also comprise of special microtubule arrangement that support them during motility.

Complete step by step answer:
To solve this question, we should know about the axoneme. The axoneme is the fibrillar bundle usually consisting of nine pairs of microtubules arranged from a ring-like structure around the single central pair. It forms the core of a cilia and flagella and is involved in providing motility to the organisms. The axoneme consists of a ring of nine microtubules doublet in primary cilia and two central microtubules added to the nine outer doublets in motile cilia. Therefore for primary cilium it shows 9+0 arrangement and for motile cilium it shows 9+2 arrangement. The axoneme cytoskeleton functions for various protein complexes that give the binding site to the motor proteins like kinesin II.
Now, the centrosome consists of two centrioles that lie at the right angles to each other. Each centriole has a cartwheel organisation. There are a total nine peripheral triplet fibrils of tubulin that are considered as a 9+0 arrangement. The basal bodies are the micro-cylinders that are found below the plasmalemma at the flagella and cilla base. The structure of the basal bodies is similar to the centrioles that are 0.1-0.2 micrometer in diameter, the 9+0 constitution along with a cartwheel structure found in the proximal region.
Thus, the correct option is ‘A’. centriole and basal bodies.

Note:
The primary cilium shows some variations in the canonical anatomy because of that the axoneme structure shows 9*2+2 type of arrangement. In this case, no dynein arms are present on the outer doublet microtubules and no pair of central microtubules is found.