Free Muscle Contraction MCQs with Answers
66 Muscle Contraction MCQs from Biology, each with the correct answer and a written explanation of why it is correct. Free and unlimited, with no account needed.
Muscle contraction is explained by the sliding filament model, in which myosin heads pull actin filaments within sarcomeres using ATP. The topic covers calcium, troponin, tropomyosin, the neuromuscular junction and relaxation, with attention to how filament length stays almost constant while the sarcomere shortens.
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66 questions · page 4 of 4
- A. Two I bands
- B. Two A bands
- C. Two M lines
- D. Two Z lines
Explanation: A sarcomere is the basic structural and functional unit of a muscle fiber, specifically within striated muscle such as skeletal and…
Correct answer: Two Z lines- A. Skeletal muscles
- B. Smooth muscles
- C. Cardiac muscles
- D. All of the above
Explanation: Smooth muscles are uniquely adapted to sustain long-term contractions with minimal energy consumption.
Correct answer: Smooth muscles- A. Released from the sarcoplasmic reticulum into the sarcoplasm
- B. Transported back from the sarcoplasm into the sarcoplasmic reticulum
- C. Further released from the sarcoplasmic reticulum into the sarcoplasm
- D. Remain constant without any movement
Explanation: During muscle relaxation, calcium ions are actively transported back from the sarcoplasm into the sarcoplasmic reticulum, which decreases…
Correct answer: Transported back from the sarcoplasm into the sarcoplasmic reticulum- A. I-Line
- B. A-Line
- C. Z-Line
- D. M-Line
Explanation: Option C is correct. The sarcomere is the region of a myofibril between two successive Z-lines.
Correct answer: Z-Line- A. Sodium
- B. Calcium
- C. Magnesium
- D. Potassium
Explanation: Option B is correct. According to the sliding filament hypothesis, the release of calcium ions from the sarcoplasmic reticulum causes the…
Correct answer: Calcium- A. Adenosine triphosphate, Lactic acid
- B. Adenosine triphosphate, Ionic imbalance
- C. Glucose, Lactic acid
- D. Glucose, Ionic imbalance
Explanation: Muscle fatigue occurs when muscles are unable to generate force or contract due to a combination of factors. The two main factors are: 1.
Correct answer: Adenosine triphosphate, Lactic acid