Question

Read the following statements:
(i) Cilia and flagella work like oars
(ii) Cilia are relatively longer than flagella
(iii) Prokaryotic and eukaryotic flagella are structurally similar
(iv) Cilia and flagella are covered with plasma membrane in eukaryotes
(v) The core of cilia/flagella is called axoneme which has nine pairs of doublets or radially arranged peripheral microtubules and a pair of centrally located microtubules.
How many of the given statements are correct?

• A. Three
• B. Two
• C. Four
• D. Five

Answer 1

The correct option is B Two

Cilia are small structures which work like oars causing the movement of either the cell or the surrounding fluid. Flagella are longer and responsible for cell movement. Flagella are often longer than cilia, about 50-100 µm in length, and there are rarely more than two per cell. they provide movement by an undulatory motion and are typically found as the motile organelle of animal sperm and some plant male gametes.

Prokaryotic and eukaryotic flagella are different in the structure but their function is similar as they are used for the locomotion in prokaryotes while in gametes of eukaryotes are also used for movement.

In eukaryotic cells, cilia and flagella contain the motor protein dynein and microtubules, which are composed of linear polymers of globular proteins called tubulin. A plasma membrane surrounds the entire axoneme complex, which is attached to the cell at a structure termed the basal body (also known as a kinetosome).

The study of a cilium or the flagellum shows that they are covered with plasma membrane. Their core is called axoneme, it possesses a number of microtubules running parallel to the long axis. The axoneme usually has nine pairs of doublets of radially arranged peripheral microtubules, and a pair of centrally located microtubules. Such an arrangement of axoenmal microtubules is referred to as the 9+2 array.

Hence the correct answer is (B)