Biology

Nervous System and Neurons

1,164 Questions

The nervous system and neurons section covers the structural and functional aspects of the human nervous system. Topics include nerve fibers, the myelin sheath, and sympathetic nervous system functions. This material is crucial for general science preparation in various competitive exams.

Neuron structureMyelin sheath productionSympathetic nervous systemCranial and spinal nervesParasympathetic functions

Nervous System and Neurons Questions

Multiple choice biology animal tissue types of neuron nervous tissue neural tissues

Direction of nerve impulse is reversed in nerve with.

  1. Axo-axonic

  2. Axo-dendritic

  3. Both A and B

  4. None of the above
Reveal answer Fill a bubble to check yourself
A Correct answer
Explanation

Answer is option A i.e. "Axo-axonic"
Axo-axonic is a type of neural structure synapse between two axons. In case case, the axon of one neuron makes synapse with axon of the other neuron (i.e both, site of neurotransmitter release and site of receptor binding, are axons). It is essential for the transmission of nerve impulses. Axoaxonic junction modulate neuronal transmission by either inhibiting or facilitating depolarization at the presynaptic membrane.

Multiple choice biology animal tissue types of neuron nervous tissue neural tissues

Cells of the nervous system that are specialized to provide support arid protection are known as

  1. Schwann cells

  2. Axons

  3. Neurons

  4. Neuroglia
Reveal answer Fill a bubble to check yourself
D Correct answer
Explanation

Neurons feature many thin projecting fibres called axons, which penetrate deep into tissues. They are able to communicate with other cells by chemical or electrical means at synapses. Neuronal function is supported by neuroglia, specialized cells which provide nutrition, mechanical support, and protection.

So, the correct option is 'Neuroglia'.

Multiple choice biology animal tissue types of neuron nervous tissue neural tissues

Most of the human neurons are

  1. Multipolar

  2. Bipolar

  3. Unipolar

  4. Pseudo-unipolar
Reveal answer Fill a bubble to check yourself
A Correct answer
Explanation

a) Multipolar neurons have more than two processes emanating from the neuron cell body. They are mainly located in central nervous system and are most common type of human neurons.

b) Bipolar neurons are relatively rare. They are sensory neurons found in olfactory epithelium, the retina of the eye, and ganglia of the vestibulocochlear nerve.
c) A unipolar neuron is a type of neuron in which only one protoplasmic process (neurite) extends from the cell body. 
d) Pseudounipolar neurons have an axon that is split into two different branches, one running into the periphery while the other running into the spinal cord. It is different from a conventional unipolar neuron because it lacks a separate dendritic process
So, the correct answer is 'Multipolar'

Multiple choice biology animal tissue types of neuron nervous tissue neural tissues

Unipolar nerve cell means _______________.

  1. Nerve cell with one dendron

  2. Nerve cell with many dendrons

  3. Nerve cell without dendron

  4. None of the above
Reveal answer Fill a bubble to check yourself
C Correct answer
Explanation
  • Unipolar nerve cell means Nerve cell without dendron. They have only one structure extending from the soma(cell body).
  • Unipolar neurons are common in insects, where the cell body is often located at the periphery of the brain and is electrically inactive.
  • Hence Unipolar nerve cell means Nerve cell without dendron.
  • So, the correct answer is 'Nerve cell without dendron'.
Multiple choice biology animal tissue types of neuron nervous tissue neural tissues

Which system transmits impulses between different parts of the body?

  1. Musculoskeletal system

  2. Endocrine system

  3. Circulatory System

  4. Nervous system

  5. Reproductive system
Reveal answer Fill a bubble to check yourself
D Correct answer
Explanation

A complex network of nerve cells or neurons forms the nervous system. This system is responsible for transmitting electrical impulses throughout the body.

So, the correct answer is 'Nervous system'.

Multiple choice biology animal tissue types of neuron nervous tissue neural tissues

The nerves that carry the messages towards the CNS from sense organs are __________.

  1. Afferent neurons

  2. Efferent neurons

  3. Interneurons

  4. none of the above
Reveal answer Fill a bubble to check yourself
A Correct answer
Explanation
A. Neurons that receive information from our sensory organs (e,g. eye, skin) and transmit this input to the central nervous system (CNS) are called afferent neurons.
B. Neurons that send impulses from the CNS to our limbs and organs are called efferent neurons.
C. Interneurons create neural circuits, enabling communication between sensory or motor neurons and the CNS.
So, the correct answer is 'Afferent neurons'.
Multiple choice biology animal tissue types of neuron nervous tissue neural tissues

Neural proteins are mainly synthesized in__________

  1. Cell body of neuron

  2. Axon

  3. Dendrites

  4. Synapses
Reveal answer Fill a bubble to check yourself
C Correct answer
Explanation

  • The human body is made up of trillions of cells. Cells of the nervous system called nerve cells or neurons, are specialized to carry "messages" through an electrochemical process. Neurons carry out basic cellular processes such as protein synthesis and energy production.
  • Protein synthesis in the extensions of nerve cells, called dendrites, Local protein synthesis in dendrites, not in the cell body of nerves, provides the ability to respond rapidly and selectively to external stimuli. 

So the answer is 'Dendrites'. 

Multiple choice biology animal tissue types of neuron nervous tissue neural tissues

Largest number of cell bodies of neuron in our body are found in the_________.

  1. Retina

  2. Spinal cord

  3. Brain

  4. Tongue
Reveal answer Fill a bubble to check yourself
C Correct answer
Explanation
The largest number of cell bodies of neurons in our body is found in the brain.
The human brain is the main organ of the human nervous system. It is located in the head, protected by the skull. It has the same general structure as the brains of other mammals, but with a more developed cerebral cortex.
The human brain is composed of neurons, glial cells, and blood vessels.
Multiple choice biology animal tissues, morphology and anatomy of cockroach types of neuron nervous tissue neural tissues

Myelin sheath of nerve fibres is produced by

  1. Axon

  2. Connective tissue

  3. Schwann cells

  4. Neuroglia
Reveal answer Fill a bubble to check yourself
C Correct answer
Explanation
  • Myelin is a layered substance made of phospholipid, cholesterol and protein that covers the axons of the neurons.
  • It insulates the nerve impulses from the surrounding nerve fibres. 
  • It also increases the speed of impulses through nerve axons.
  • It is formed in the central nervous system by glial cells called the oligodendrocytes.
  • Whereas, in the peripheral nervous system they are produced by Schwann cells.
  • So, the correct answer is 'Schwann cells'.
Multiple choice biology animal tissues, morphology and anatomy of cockroach types of neuron nervous tissue neural tissues

The characteristic of a nerve cell that relates directly to its function is its-

  1. Long extensions.

  2. Flat shape.

  3. Ability to change shape.

  4. Ability to engulf bacteria.
Reveal answer Fill a bubble to check yourself
A Correct answer
Explanation

The long extensions of a nerve cell (axons and dendrites) are essential for its function of transmitting signals over long distances within the body.

Multiple choice biology animal tissues, morphology and anatomy of cockroach types of neuron nervous tissue neural tissues

Bipolar neurons are present in the

  1. Retina of eyes

  2. Olfactory epithelium

  3. Spinal ganglia at embryonic stage

  4. All of the above
Reveal answer Fill a bubble to check yourself
D Correct answer
Explanation

Bipolar neurons are specialised neurons that have two cytoplasmic extensions. Out of which one serves as an axon and other serves as a dendrite both having similar branches. They function in sight, hearing, tasting, etc. They are located in the retina of the eyes, the roof of the nasal cavity, inner ear. 

So, the correct answer is option D.

Multiple choice zoology locomotion and reproduction flagella other cell components single membrane bound organelles

Number of dynein arms

  1. Four attached to subfibre B

  2. Two attached to subfibre B

  3. Two attached to subfibre A

  4. Four attached to subfibre A
Reveal answer Fill a bubble to check yourself
C Correct answer
Explanation
  • Dynein arms refer to the structures that extend clockwise from one tubule of each microtubule (nine doublets) towards the adjacent doublet in the axoneme of cilia or flagella.
  • Each axoneme contains eight or nine dynein heavy chains.
  • The inner and outer dynein arms are two-headed structures which contain two heavy chains each.
  • So, the correct answer is 'Two attached to sub fibre A'.
Multiple choice zoology animal diversity - i (inverterbrate phyla) structure of earthworm earthworm - morphology, integumentary system , respiration and nervous system adaptations

In earthworm, neurons are

  1. Sensory

  2. Motor

  3. Mixed

  4. None of these
Reveal answer Fill a bubble to check yourself
C Correct answer
Explanation

The neurons in the earthworm are myelinated so they are covered with insulating fats. The neurons in earthworm are sensory in nature as well as motor and adjuster or associated neurons. Sensory carries the information from the brain while the motor carries the impulse back to the effector organs.

So, the correct answer is option C.