Consider the following statements:

I: The resting axonal membrane is nearly impermeable to sodium ions.
II: Depolarization of the axonal membrane is due to the influx of sodium ions.
III: The size of the action potential, if produced, does not depend on the strength of the stimulus.

Which of the above statements are true?

1. I and II only

2. I and III only

3. II and III only

4. I, II and III

Subtopic:  Action Potential |
From NCERT
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Consider the following statements:

I. Acetylcholine is released at the electric synapse.

II. Electric synapses are faster.

III. It is more difficult to regulate an electric synapse with respect to a chemical synapse.

Which of the above statements are true?

1. I and II only

2. I and III only

3. II and III only

4. I, II, and III

Subtopic:  Synapse |
 69%
From NCERT
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Receptor sites for neurotransmitters are present on
1. membrances of synaptic vesicles
2. pre-synaptic membrane
3. tips of axons
4. post-synaptic membrane

Subtopic:  Synapse |
 81%
From NCERT
NEET - 2017
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Good vision depends on adequate intake of carotene rich food.

Select the best option from the following statements.

I. Vitamin-A derivatives are formed from carotene.
II. The photopigments are embedded in the membrane discs of the inner segment.
III. Retinal is a derivative of vitamin-A.
IV. Retinal is a light absorbing part of all the visual photopigments.

(1) (I) and (II)

(2) (I), (III) and (IV)

(3) (I) and (III)

(4) (II), (III) and (IV)

Subtopic:  Basic Anatomy of Human Eye: 1 (OLD NCERT) | Basic Anatomy of Human Eye: 2 (OLD NCERT) | Basic Anatomy of Human Eye (OLD NCERT) |
 57%
NEET - 2017
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Myelin sheath is produced by
(1) Schwann cells and Oligodendrocytes

(2) Astrocytes and Schwann cells

(3) Oligodendrocytes and Osteoclasts

(4) Osteoclasts and Astrocytes

Subtopic:  Neuroanatomy |
 90%
NEET - 2017
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Choose the correct statement.
(1) Nociceptors respond to changes in pressure

(2) Meissner's corpuscels are thermoreceptors

(3) Photoreceptors in the human eye are depolarised during darkness and become hyperpolarised in response to the stimulus 

(4) Receptors do not produce graded potentials

Subtopic:  Huma Eye: Accommodation (OLD NCERT) |
 80%
NEET - 2016
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Destruction of the anterior horn cells of the spinal cord would result in loss of 

(1) sensory impulses

(2) voluntary motor impulses

(3) commissural impulses

(4) integrating impulses

Subtopic:  Motor Functions of Spinal Cord |
 54%
NEET - 2015
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Stimulation of a muscle fibre by a motor neuron occurs at

1. the neuromuscular junction

2. the transverse tubules

3. the myofibril

4. the sacroplasmic reticulum

Subtopic:  Synapse |
 87%
NEET - 2014
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Which one of the following statements is not correct?

1. Retinal is the light absorbing portion of visual photopigments 

2. In retina the rods have the photopigment rhodopsin, while cones have three different

photopigments

3. Retinal is a derivative of vitamin-C

4. Rhodopsin is the purplish red protein present in rods only 

Subtopic:  Human Eye: Adaptation (OLD NCERT) |
 87%
NEET - 2014
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A diagram showing axon terminal and synapse is given. Identify correctly A-D.

1. A- Receptor                  C-synaptic Vesicles

2. B-Synaptic connection   D-K+

3. A-Neurotransmitter        B-Synaptic cleft

4. C-neurotransmitter        D-Ca2+        

Subtopic:  Synapse |
 79%
From NCERT
NEET - 2013
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