To determine the correct answer, we need to evaluate both the assertion and the reason provided, and see if the reason adequately explains the assertion.
Assertion (A): Reflex actions do not involve thinking.
Reason (R): Most reflex actions are controlled by the spinal cord.
Let's break down each statement:
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Understanding Reflex Actions:
- Reflex actions are involuntary and automatic responses to stimuli.
- They occur without the involvement of the conscious part of the brain.
- This lack of direct conscious involvement is why reflex actions do not involve "thinking" in the usual sense.
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Role of the Spinal Cord:
- The spinal cord is primarily responsible for the control of many reflex actions.
- When a reflex action is triggered, the sensory neurons send a signal to the spinal cord, which then sends an immediate response signal back to the muscles, bypassing the brain.
- Thus, the spinal cord facilitates quick reactions without waiting for brain processing, which supports the assertion that these actions do not involve thinking.
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Analyzing the Relationship:
- Since reflex actions are controlled by the spinal cord, which operates independently of conscious brain functions, this is why they do not involve thinking.
- Therefore, the reason given explains the assertion correctly.
Conclusion: Both the assertion and the reason are true, and the reason is the correct explanation of the assertion.
Final Answer: Both Assertion (A) and Reason (R) are true and Reason (R) is the correct explanation of the Assertion (A).