Assertion (A): A sprain is the twisting of a joint without dislocating it.
Reason (R) A strain is a less severe stretching or twisting of the joint.
1. Both (A) and (R) are true and (R) is the correct explanation of (A).
2. Both (A) and (R) are true but (R) is not the correct explanation of (A).
3. (A) is true but (R) is false.
4. Both (A) and (R) are false

Subtopic:  Disorders of Muscular and Skeletal System |
 65%
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What is the role of acetylcholine in muscle contraction?
1. It is used to link nerve pulse with receptors in the muscle.
2. It makes upper part of the muscle fibres degenerate 
3. The myosin heads use acetylcholine to bind to action filaments
4. It maintains contraction of a muscle in a manner similar to a brake
Subtopic:  Excitation Contraction Coupling I |
 66%
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Rigor mortis (stiffness after death) occurs due to muscle contraction. However, it lasts for 24 hours and then disappears. This is because:
1. The body looses rigidity due to decay of muscle protein
2. Proteolytic enzymes get deactivated
3. Ca2+ channels in the sarcoplasmic reticulum are closed after 24 hours
4. Cross-linkages between myosin and actin gets reformed 
 
Subtopic:  Energy for Muscle Contraction | Muscle Contraction: Other Considerations |
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Identify A, B, C and D from the table:
Red muscle fibre White muscle fibre
These are dark red  These are lighet in colour
Mitochondria is more in number. Mitochondria is less in number.
A B
These carry out mainly aerobic oxidation and can contract for a longer period without fatigue. These carry out mainly anaerobic oxidation and can get fatigued soon.
C D
 
Optons A B C D
1. More sarcoplasmic reticulum Less sarcoplasmic reticulum Muscle fibres have slow rate of contraction for long periods Muscle fibres have fast rate of contraction for long periods
2. Less sarcoplasmic reticulum More sarcoplasmic reticulum Muscle fibres have slow rate of contraction for long periods Muscle fibres have fast rate of contraction for long periods
3. Less sarcoplasmic reticulum More sarcoplasmic reticulum Muscle fibres have fast rate of contraction for long periods Muscle fibres have slow rate of contraction for long periods
 
4. Less sarcoplasmic reticulum less sarcoplasmic reticulum Muscle fibres have fast rate of contraction for long periods Muscle fibres have fast rate of contraction for long periods
Subtopic:  Skeletal Muscle: Basic Anatomy |
 60%
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Read the following statements and choose the correct option:
 A. The extensor muscles of human back reamin in sustained contraction to maintain erect posture against gravity.
 B. The extensor mucles are rich red muscle fibres with abundant mitochondria and myoglobin.

1. Statement A is correct but B incorrect.
2. Statement  B correct but A incorrect.
3. Statement A is correct and B are correct but B is not hte correct explanation of A.
4. Both the statements A and B are correct but B is not the correct explanation of A.

 
Subtopic:  Skeletal Muscle: Basic Anatomy |
 52%
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Read the following statements:
i. Scapula is situated in the dorsal part of thorax between the second and the seventh ribs
ii. The striated appearance of a myofibril is due to the distribution pattern of sarcoplasmic reticulum
iii. Myosin possess oxygen storing capacity
iv. The central hollow portion of vertebra is called neural canal
v. I-band shortens during muscle contraction
How many of the above statements are incorrect?
1. Two
2. Three
3. Four
One
 
Subtopic:  Skeletal Muscle: Myofilaments | Skeletal Muscle: Sarcomere | Appendicular Skeleton | Appendicular Skeleton: Girdle | Axial Skeleton |
From NCERT
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Find out the true (T)/ false (F) statements and choose the correct option.
I. The most abundant skeletal muscle protein is myosin
II. The length of A-band remains unchanged during muscle contraction.
III. Ileum is a part of pelvic girdle.
IV. The biggest muscle is Gluteus maximus in the buttock and the smallest is Stapedius in the middle ear
Options I II III IV
1. T T T T
2. T F T F
3. F T F T
4. T T F T
Subtopic:  Skeletal Muscle: Myofilaments | Skeletal Muscle: Sarcomere |
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Striated muscles contract because of:
1. Sliding of actin filaments on myosin filaments
2. Sliding of myosin filaments on actin filaments
3. Actin filaments sliding over another actin filament
4. Fusion of myosin filaments 
Subtopic:  Sliding Filament Theory |
 88%
From NCERT
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Find out the true (T)/false (F) statements and choose the correct option:
I. The phosphagen in the vertebrate muscle is arginine phosphate
II. The accumulation of phosphoenol pyruvic acid in muscles cause fatigue
III. Cori cycle occurs in liver and muscle
IV. ATP is synthesised in the muscle by the phosphorylation of ADP by a phosphagen
Options I II III IV
1. T T F F
2. F F T T
3. T F T F
4. F T F F
Subtopic:  Muscle Contraction: Other Considerations |
 58%
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Which of the following is correct?
1. Blood supply is absent in smooth muscles
2. In cardiac muscle fibres, sarcoplasmic reticulum is poorly developed in comparison to skeletal muscle fibres
3. Both (1) and (2)
4. ATPase enzyme required for muscle contraction is located in myosin and actin
Subtopic:  Introduction to Locomotion |
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