Question

The sites of ATPase activity in flagellum/cilium are

• A. The dynein arms of outer doublets of microtubules
• B. Outer protoplasmic sheath
• C. Inner sheath
• D. Central tubules of axoneme

Answer 1

The correct option is A The dynein arms of outer doublets of microtubules

Cilia and flagella move because of the interactions of a set of microtubules inside. Collectively, these are called an "axoneme". Two of these microtubules join to form one doublet in the cilia or flagella. Cytoplasmic dynein contains approximately twelve polypeptide subunits, two identical "heavy chains", 520 kDa in mass, which contain the ATPase activity and is thus responsible for generating movement along the microtubule.
So, the correct answer is option A.