The cerebral cortex has which type of neurons?

$S$ - Statement: The myelin sheath around a nerve fiber contains lipids.
$R$ - Reason: This sheath prevents the impulse from leaking into adjacent nerve fibers.

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:

Cytoplasm with typical cell organelles and $Nissl's$ granules is present in the:

Which of the following is considered the structural and functional unit of neural tissue?

Nissl's granules are present in the ....... and are made up of ....... respectively.