Question

Which cell organelle is absent in neurons?
A. Mitochondria
B. Ribosomes
C. Centrioles
D. Nucleus

Answer 1

Hint: Cell organelles are the specialized entity that are present inside the cell. Each cell organelle performs a particular function. Cell organelles are the organs of the cell.

Complete Answer:
Neuron: Neurons are also called nerve cells. Neurons are the basic and functional unit of the brain. They are responsible for transmitting the signals to the other nerve cells, muscles, brain , glands and various body parts.
 Structure of neurons consist of three parts-
- Cell body
- Axon
- Dendrite

A. Mitochondria – Mitochondria is also called the powerhouse of the cell. It is responsible for producing energy in the form of ATP (adenosine triphosphate). They are the membrane bound cell organelles. They are also called semi autonomous organelles because they have their own DNA and ribosomes.
B. Ribosomes – Ribosomes are the minute particles that consist of the RNA. They are the protein factory site. Ribosomes are responsible for making proteins, They may be freely present in the cytoplasm or may be attached with the endoplasmic reticulum.
C. Centrioles – Centriole is a cylindrical organelle. This organelle is composed of a protein which is called tubulin. Centrioles are only present in the eukaryotic animal cells. Centrioles are responsible for dividing the cell into two.
D. Nucleus – Nucleus is a double membrane bound cell organelle. Nucleus is also called the brain centre of the cell. Nucleus contain the genetic information in the form of DNA (deoxyribo nucleic acid). DNA is the hereditary material which gets transferred from the parents to the offspring.
Neurons lack the centrioles which prevent the neurons to divide as centrioles are responsible for dividing the cell into two.

So, the option C is the correct option for this question.

Note: Neurons make their communication with each other via some connections called synapse. Neurons are classified into the three types-
1. Sensory neurons – These neurons respond to the stimuli like touch, sound, light, etc. that affect the cells of sensory organs.
2. Motor neurons – These neurons receive signals from the brain and spinal cord to control many things like muscular activities.
3. Interneurons – Interneurons connect the neurons to other neurons.