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Assertion: During muscle contraction , a...

Assertion: During muscle contraction , actin filaments of both the sides are pulled toward the M - line.
Reason: The heads on the two ends of the thick filaments are oriented in opposite directions.

A

if both assertion and reason are true and the reason is correct explanton of Assertion

B

IF both assertion and reason and reason are true but reason is not a correct explanation of assertion

C

IF assertion is true and reason is wrong

D

if both assertion and reason are wrong

Text Solution

AI Generated Solution

The correct Answer is:
To solve the question, we need to analyze both the assertion and the reason provided. ### Step-by-Step Solution: 1. **Understanding the Assertion**: - The assertion states that during muscle contraction, actin filaments on both sides are pulled toward the M-line. - This is true because during muscle contraction, the sarcomere shortens, and the actin filaments slide toward the center (M-line) due to the action of myosin heads. 2. **Understanding the Reason**: - The reason given is that the heads on the two ends of the thick filaments (myosin) are oriented in opposite directions. - This is also true. The myosin heads on the thick filaments are indeed oriented in opposite directions, which allows them to pull the actin filaments toward the M-line from both sides. 3. **Evaluating the Relationship**: - The reason explains why the assertion is true. The orientation of the myosin heads allows for the pulling of actin filaments toward the M-line during contraction. 4. **Conclusion**: - Since both the assertion and reason are true, and the reason correctly explains the assertion, the correct answer is that both assertion and reason are true, and the reason is the correct explanation of the assertion. ### Final Answer: - Both assertion and reason are true, and the reason is the correct explanation of the assertion.
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