Question

Assertion (A): Reflex actions do not involve thinking.
Reason (R): Most reflex actions are controlled by the spinal cord.

• A. Both Assertion (A) and Reason (R) are true and Reason (R) is the correct explanation of the Assertion (A).
• B. Both Assertion (A) and Reason (R) are true, but Reason (R) is not the correct explanation of the Assertion (A).
• C. Assertion (A) is true, but Reason (R) is false.
• D. Assertion (A) is false, but Reason (R) is true.

Hint:

Reflex arc pathway: Stimulus \(\Rightarrow\) Receptor \(\Rightarrow\) Sensory neuron \(\Rightarrow\) Spinal cord (interneuron) \(\Rightarrow\) Motor neuron \(\Rightarrow\) Effector \(\Rightarrow\) Response.
Brain is not involved, so no thinking required!

Answer 1

The Correct Option is A

Step 1: Analyze Assertion (A).
Assertion (A): "Reflex actions do not involve thinking."

• Reflex actions are automatic, rapid, and involuntary responses to stimuli.
• They occur without conscious thought or decision-making.
• Example: Pulling hand away from a hot object happens instantly without thinking.
• Therefore, Assertion (A) is TRUE.

Step 2: Analyze Reason (R).
Reason (R): "Most reflex actions are controlled by the spinal cord."

• Reflex arcs involve sensory neurons, motor neurons, and often interneurons in the spinal cord.
• The spinal cord processes the reflex action without involving the brain.
• Examples: Knee jerk reflex, withdrawal reflex are controlled by spinal cord.
• Therefore, Reason (R) is TRUE.

Step 3: Check if Reason (R) correctly explains Assertion (A).

• Reflex actions do not involve thinking BECAUSE they are controlled by the spinal cord.
• Since the spinal cord handles the response, signals do not need to travel to the brain for conscious processing.
• This direct spinal cord involvement bypasses the thinking centers of the brain.
• Thus, Reason (R) is the correct explanation of Assertion (A).

Final Answer: (A) Both Assertion (A) and Reason (R) are true and Reason (R) is the correct explanation of the Assertion (A).