Biology

Nervous System and Neurons

1,224 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 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.

Multiple choice zoology animal diversity - i (inverterbrate phyla) structure of earthworm earthworm - morphology, integumentary system , respiration and nervous system adaptations
Which of the following statements is incorrect about the nervous system earthworm?

  1. Nervous system is basically represented by ganglia arranged on ventral nerve cord

  2. In 3rd and 4th segment, the nerve cord bifurcates and joins the cerebral ganglia dorsally to form a nerve ring.

  3. The cerebral ganglia along with other nerves in the ring integrate sensory input as well as command muscular responses of the body

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

The nervous system of earthworm consists of cerebral ganglia or bilobed brain present dorsally, sub pharygeal ganglia, circum pharyngial ganglia and ventral nerve cord. 

So, the correct answer is 'Nervous system is basically represented by ganglia arranged on ventral nerve cord'

Multiple choice zoology animal diversity - i (inverterbrate phyla) structure of earthworm earthworm - morphology, integumentary system , respiration and nervous system adaptations

Read the given statements and select the incorrect one.

  1. In Hydra, all neurons are similar and join to form a nerve net.

  2. In Earthworms, the nervous system consists of a dorsal nerve cord, paired ganglia, and segmental nerves.

  3. Brain is present in insects

  4. Planaria has two nerve cords that join to form rudimentary brain
Reveal answer Fill a bubble to check yourself
B Correct answer
Explanation

The nervous system of an earthworm consists of a ventral nerve cord (not dorsal), paired ganglia, and segmental nerves. Therefore, the statement in option B is incorrect.

Multiple choice botany caskets of life the cell structure multicellular organisms number and shape of cells

Match the following:
A                                                                                B
A. Barr body                             1   Gives a grey colour to the
                                                          cell body
B. Purkinje cells                       2. Condudion muscles of
                                                        heart.

C. Nissl bodies                           3. Present in neurilemma
D. Schwann cell                          4. Certain neurons having
                                                           flask shaped cylons.

E. Purkinje fibres                          5. Found in cylons of female.
The correct pairing is.

  1. 5, 4, 1, 3, 2

  2. 3, 2, 5, 1, 4

  3. 5, 2, 1, 3, 4

  4. 4, 3, 2, 5, 1
Reveal answer Fill a bubble to check yourself
A Correct answer
Explanation

Barr bodies are found in the cells of females (5). Purkinje cells are flask-shaped neurons in the cerebellum (4). Nissl bodies give a grey color to the cell body (1). Schwann cells are present in the neurilemma (3). Purkinje fibers are conduction muscles of the heart (2).

Multiple choice biology sensory organs of humans - sense organs ear : the organ of hearing and equilibrium ear and its function ear

The impulse of sound is conducted to the brain by 

  1. Olfactory nerve

  2. Auditory nerve

  3. Optic nerve

  4. Trachea nerve
Reveal answer Fill a bubble to check yourself
B Correct answer
Explanation

The olfactory nerve is the second cranial nerve which transmits the nerve impulses from olfactory receptors, receptors of sense the smell that are located in nasal epithelium of roof of the nasal cavity, to the brain.

Optic nerve consists of ganglion cell fibres from the innermost layer of the retina and serves to transmit the impulse from medial and lateral halves of the same eye to brain. 
Auditory nerve receives axons of neurons that being around organ of Corti and transmits the auditory information from the cochlea to brain. Trochlear nerve is the fourth cranial nerve relays motor information from the brain to superior oblique eye muscles and thus regulates the up, down and outward movements of the eye ball. 
Therefore, the correct answer is option B.

Multiple choice biology sensory organs of humans - sense organs ear : the organ of hearing and equilibrium ear and its function ear

Statoreceptors are located in

  1. Cristae

  2. Maculae

  3. Both A and B

  4. Cochlea
Reveal answer Fill a bubble to check yourself
C Correct answer
Explanation
Statoreceptors are the receptors that sense changes in equilibrium and orientation of body. They are located in Cristae and Maculae. Crista is a projecting ridge of ampulla which is the swollen base of bony canal in inner ear. Macula is a projecting ridge of saccule and utricle which are otolith organs in vestibular apparatus of inner ear. Crista and macula are specific receptors of vestibular apparatus that are responsible for maintaining balance of body and posture.
So, the correct answer is 'Both A and B'.
Multiple choice biology sensory organs of humans - sense organs ear : the organ of hearing and equilibrium ear and its function ear

Static equilibrium is maintained by

  1. Sacculus

  2. Utriculus

  3. Semicircular canals

  4. Both A and B
Reveal answer Fill a bubble to check yourself
D Correct answer
Explanation
Static equilibrium is maintained by vestibular apparatus of inner ear. It contains saccule and utricle (or sacculus and utriculus). These are the otolith organs present in inner ear. When the position of head changes due to movement, otoliths present in gelatinous membrane come in contact with the sensory hair cells and impulses are generated. The impulses are carried through the auditory nerve to cerebellum for interpretation which then sends reflex signals and static balance is restored.
So, the correct answer is 'Both A and B'.
Multiple choice biology sensory organs of humans - sense organs ear : the organ of hearing and equilibrium ear and its function ear

The sensory receptors that respond to sound, develop receptor potentials when their

  1. Hairs are absent

  2. Pigments absorb pressure

  3. Surface proteins are altered by a change in pH

  4. Sodium-potassium pumps become deactivated.
Reveal answer Fill a bubble to check yourself
A Correct answer
Explanation
The organ of Corti is a structure located on the basilar membrane which contains hair cells that act as auditory receptors. Movements of the basilar membrane bend the hair cells, pressing them against the technical membrane. As a result, nerve impulses are generated in the association afferent neurons. These impulses are transmitted by the afferent fibers via auditory nerves to the auditory cortex of the brain, where the impulses are analyses and the sound is recognized.
So the correct answer is 'Hairs are absent'.
Multiple choice biology sensory organs of humans - sense organs ear : the organ of hearing and equilibrium ear and its function ear

Deformation of sensory dendrites is required to establish a nerve impulse in all of the following except

  1. gustatory hair cells

  2. organ of Corn

  3. Pacinian corpuscles

  4. lateral line organs
Reveal answer Fill a bubble to check yourself
A Correct answer
Explanation

The sensory nervous system and the motor nervous system are a part of the nervous system responsible for the processing of sensory information. A sensory system consists of sensory neurons, neural pathways, and parts of the brain involved in sensory perception.

So, the correct option is 'gustatory hair cells'.

Multiple choice biology life processes: control and coordination structure and function of brain human brain nervous and endocrine system in humans

Assertion: In man, only peripheral nervous system is present.

Reason: The peripheral nervous system includes nerves coursing between the central nervous system and different parts of the body.

  1. If both the assertion and the reason are true and the reason is the correct explanation of the assertion

  2. If both the assertion and the reason are true and the reason is not the correct explanation of the assertion

  3. If the assertion is true and the reason is false

  4. If both the assertion and the reason is false

  5. If the assertion is false but the reason is true
Reveal answer Fill a bubble to check yourself
E Correct answer
Explanation

The nervous system of human comprises of Central Nervous System - comprises of brain and spinal cord. Peripheral Nervous System - comprises of nerves present between brain and body parts.