Question

Nissl granules occur in which part and what is their function?
(a) Neurons and the site of protein synthesis.
(b) Blood and help in nutrition and excretion.
(c) Sarcoplasm and help in contraction.
(d) Cell and secrete mucus.

Answer 1

Hint: It is the longest cell in the human body, which transmits information throughout the body in the form of impulse.

Complete answer:
Nissl granules occur in the neurons and they are the site for protein synthesis. Nissl granules are the substances found in the neurons which are a large granular type of body. These granules are rough endoplasmic reticulum (RER) with rosettes of free ribosomes. These are very useful for protein synthesis and also help to transport these proteins to the part known as cyton.

Additional Information: The nervous system transmits signals to and from different parts of the body. It has a complex collection of nerves and specialized cells known as neurons that transmit signals to other nerve cells, muscle, or gland cells.
Neurons have three distinct parts-
1) Soma- a cell body that contains a nucleus, smooth and rough endoplasmic reticulum, Golgi apparatus, mitochondria, and other cellular components.
2) Axon- a long slender projection that conducts electrical impulses away from the cell body to the structures at opposite ends of the neuron—axon terminals, which can then pass the impulse to another neuron.
3) Dendrites- tree-like structures extending away from the cell body, that receive messages from other neurons. These parts help them to send and receive chemical and electrical signals.

So, the correct answer is, ‘Neurons and is the site of protein synthesis’.

Note:
-The axon hillock, which serves as a junction between the cell body and the axon.
-The synapse is the chemical junction between the axon terminals of one neuron and the dendrites of the next.
-Nearly 86 billion neurons work together within the nervous system to communicate with the rest of the body.
-Axon arises from cyton and cyton is the central or cell body of a neuron containing the nucleus.