Identify the function of a neuron.

In polio,the legs become paralyzed and useless. What is the reason for this?

Nissl's granules are found in the cyton of nerve cells. These have an affinity for basic dyes. The granules are made up of:

Which one of the following is not essentially a part of the nervous system?

Multiple sclerosis is caused by .............

Choose the correct statements about Nissl's granules from the codes given below:
$I.$ There are regular masses of ribosomes
$II.$ There are irregular masses of ribosomes and $ER$
$III.$ There are granular bodies
$IV.$ They synthesise proteins in the cell