Identify the function of a neuron.

In a neuron,ion channels are made of $.....P....$ and are located in $.....Q.....$.
$\quad\quad P\quad\quad Q$

Identify $X$ and $Y$ in the given figure.

Which of the following statements are correct?
$I$. Dendrites are long fibres with branched distal ends.
$II$. Axons are short fibres which arise from the cell body.
$III$. The cell body of a neuron contains cytoplasm,a nucleus with cell organelles,and Nissl's granules.
$IV$. Dendrites transmit nerve impulses away from the cell body to a synapse.
The correct option is:

Which of the following statements is $INCORRECT$?

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