The neuromuscular junction, the site where a motor neuron communicates with a muscle fiber to initiate contraction, involves the release of:
1. Dopamine
2. Acetylcholine
3. Serotonin
4. Glutamate
Subtopic:  Sliding Filament Theory | Muscle Contraction: Other Considerations |
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Level 1: 80%+
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Mechanism of muscle contraction is best explained by

1. Sliding Filament Theory

2. Sliding fibre theory

3. Sliding myofibre theory

4. Muscle sliding theory

Subtopic:  Sliding Filament Theory |
 97%
Level 1: 80%+
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Muscle fatigue is primarily attributed to the accumulation of which metabolic by-product?
1. Lactic acid
2. ATP
3. Glucose
4. Glycogen
Subtopic:  Sliding Filament Theory | Muscle Contraction: Other Considerations |
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Level 1: 80%+
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Name the ion responsible for unmasking of active sites for myosin for cross-bridge activity during muscle contraction:

1. Calcium 2. Magnesium
3. Sodium 4. Potassium
Subtopic:  Skeletal Muscle: Myofilaments | Sliding Filament Theory |
 95%
Level 1: 80%+
NEET - 2016
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What triggers the release of calcium ions from the sarcoplasmic reticulum during muscle contraction?
1. The formation of a neuromuscular junction
2. The action of tropomyosin
3. The release of a neurotransmitter, acetylcholine, at the neuromuscular junction
4. The breakdown of glycogen in muscle fibres
Subtopic:  Sliding Filament Theory |
 91%
Level 1: 80%+
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During muscle contraction, which of the following retains its length?
1. Sarcomere
2. I-bands
3. A-bands
4. H-zones
Subtopic:  Sliding Filament Theory | Muscle Contraction: Other Considerations |
 91%
Level 1: 80%+
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Consider the given two statements:
Statement I: Calcium ions play a crucial role in muscle contraction.
Statement II: Calcium ions bind to troponin, causing conformational changes that expose binding sites on actin.
1. Statement I is correct; Statement II is correct
2. Statement I is correct; Statement II is incorrect
3. Statement I is incorrect; Statement II is correct
4. Statement I is incorrect; Statement II is incorrect
Subtopic:  Sliding Filament Theory | Muscle Contraction: Other Considerations |
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Level 1: 80%+
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During muscle contraction, which of the following bands or zones remains constant in length?
1. A-band
2. I-band
3. H-zone
4. Z-line
Subtopic:  Skeletal Muscle: Sarcomere | Sliding Filament Theory | Muscle Contraction: Other Considerations |
 90%
Level 1: 80%+
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During muscular contraction, which of the following events occur?
(a) 'H' zone disappears
(b) 'A' band widens
(c) 'I' band reduces in width
(d) Myosin hydrolyzes ATP, releasing the ADP and Pi
(e) Z-lines attached to actins are pulled inwards

Choose the correct answer from the options given below.
1. (b), (c), (d), (e) only
2. (b), (d), (e), (a) only
3. (a), (c), (d), (e) only
4. (a), (b), (c), (d) only

Subtopic:  Skeletal Muscle: Myofilaments | Sliding Filament Theory |
 91%
Level 1: 80%+
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In the resting state, a subunit of troponin 
1. Provides the site for attachment of myosin
2. Masks the active binding sites for myosin in the actin filaments 
3. Forms a cross bridge with meromyosin 
4. Masks the binding site of actin on myosin 

 
Subtopic:  Sliding Filament Theory |
 89%
Level 1: 80%+
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