Which of the following has non-myelinated nerve fibres?

Match List $- I$ with List $- II$:

List $- I$	List $- II$
$a$. Multipolar neuron	$i$. Somatic neural system
$b$. Bipolar neuron	$ii$. Cerebral cortex
$c$. Myelinated nerve fibre	$iii$. Retina of eye
$d$. Unmyelinated nerve fibre	$iv$. Spinal nerves

Choose the correct answer from the options given below:

Which of the following is the structural and functional unit of the nervous system?

Select the correct option for dendrites and axons.
$I -$ Short fibers,$II -$ Long fibers,$III -$ Transmit impulses away from the cell body,$IV -$ Transmit impulses towards the cell body,$V -$ Highly branched fibers,$VI -$ Unbranched fibers
Dendrites $\quad$ $\quad$ Axon

Where are $Nissl$ granules absent?

Unipolar neurons are found usually in the embryonic stage. They have