Which lipid-rich layer surrounds the nerve fiber?

Where are the $Nissl$ granules found?

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:

The covering of $Schwann$ cells is associated with:

Where are Nissl granules found and what is their function?

Which of the following statements is correct regarding a neuron?