The formation of cilia and flagella in living cells is carried out with the help of

Analyze the question: It asks which cell organelle helps in forming cilia and flagella, the hair-like structures used for movement.

Explain the concept: Cilia and flagella are built from microtubules arranged in a "9+2" pattern. Microtubules are organized by structures called centrioles. Centrioles are cylindrical organelles made of 9 triplets of microtubules. They move to the cell surface and become basal bodies, which act as the base and template from which cilia and flagella grow.

Step-by-step solution:

1. Ribosome (A): Makes proteins. It is not specifically responsible for forming cilia or flagella.
2. Lysosome (B): Contains digestive enzymes to break down waste and worn-out cell parts. It is not involved.
3. Centriole (C): Forms the basal body that gives rise to cilia and flagella. It also helps form the spindle fibres during cell division. This fits.
4. Plastid (D): Found in plant cells, e.g., chloroplasts for photosynthesis. It is not involved.

Answer: C. Centriole

Exam tip: Remember "Centriole = Cilia". Both start with C, and centrioles are also linked to the spindle during cell division. When you see "cilia," "flagella," or "spindle fibres," think centriole.