Question

Unipolar neurons can be traced in
A. Spinal cord
B. Motor nerves
C. Retina
D. None of the above

Answer 1

Hint: A neuron is the basic functional unit of the nervous system of the body. The neurons usually consist of a cell body, an axon, and dendritic branches. A unipolar neuron is that in which there is only one neuron process or elongation called neurite. A type of pseudo unipolar neuron is found in the dorsal root ganglia.

Complete answer:
Neurons are electrically conducting cells that form the basic functional units of the nervous system. The neurons are of various types. Most of the neurons in the vertebrates are multipolar. It means that neurons consist of various processes that run in different directions but are attached to a single cell body. The general structure of a neuron consists of a cell body called soma, an axon, and dendrites. The axon is the main conducting body and the dendrites are branched structures that arise from the soma.

Some of the neurons modify to have a single process originating from the soma. These neurons are called unipolar neurons. The unipolar neurons can be further classified as true unipolar and pseudo unipolar neurons. The pseudo unipolar neurons originate normally like a multipolar neuron but later split its axon into making a single neurite. These are found in the dorsal root ganglia of the spinal cord. One of the axonal divisions goes towards the sensory organs and one goes towards the spinal cord.
Hence, option A is the correct answer.

Note:
There are various classification for neurons. Another type of neuron is a bipolar neuron. These neurons have two main processes and are found in the retina of vertebrates. The true unipolar neurons are found to be present in the cerebellum and dorsal cochlear nucleus.