Question

Arrangement of microtubules in a flagellum and a centriole is _______ and ________ respectively.

• A. $9+2$ and $9+1$
• B. $9+1$ and $9+0$
• C. $9+0$ and $9+2$
• D. $9+2$ and $9+0$

Answer 1

The correct option is D $9+2$ and $9+0$

A centriole possesses a whorl of nine peripheral fibrils. Fibrils are absent in the centre. The arrangement is, therefore, called $9+0$. Flagellum contains an axoneme of a peripheral doublet fibrils and $2$ central singlet fibrils. This arrangement is called $9+2$ or $11$ stranded.

So, the correct answer is '9+2 and 9+0'.