Question

Explain why nerve cells are long, while ciliated cells are short and have cilia?

Answer 1

Nerve cells have to carry messages in the form of electrical signals from the different parts of the body to the spinal cord and the brain and back from them to the body parts. In order to carry messages over a long distance, they have long 'arms'; hence, they are long.
Ciliated cells are short and have hair-like projections called cilia, the lashing movement of which keeps dust and germs away.