NEET Zoology Muscle Contraction Assertion Reason Question
Assertion (A): Muscle contraction is initiated by the release of calcium ions into the sarcoplasm.
Reason (R): Calcium ions bind to a subunit of troponin on actin filaments, exposing active sites for myosin.
Both A and R are true, and R explains A
Both A and R are true, but R does not explain A
A is true but R is false
A is false
Correct Answer
Detailed Explanation
The release of calcium ions into the sarcoplasm initiates muscle contraction by binding to troponin, which exposes active sites on actin filaments, allowing myosin to bind and contract the muscle. This is directly explained in the NCERT context.
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