NEET Zoology Muscle Contraction MCQ Question
Which of the following statements about muscle contraction is correct?
Calcium ions bind to troponin, exposing binding sites on actin.
Actin is present in the A-band and myosin in the I-band.
The sarcoplasmic reticulum releases calcium only during muscle relaxation.
Myosin filaments are primarily responsible for the light bands in muscle fibers.
Correct Answer
Detailed Explanation
Calcium ions bind to a subunit of troponin on actin filaments, which removes the masking of active sites for myosin, allowing contraction to occur. This is consistent with the description of muscle contraction in the NCERT context.
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