Which of the following is an example of an unconditioned response in a reflex arc?

• A. Jumping at the sound of a loud noise
• B. Blinking in response to a bright light
• C. Salivating when food is placed in the mouth
• D. Learning to ride a bicycle

Answer: (C)

Verified step by step guidance

1. Understand the concept of a reflex arc: A reflex arc is a neural pathway that controls a reflex action. It typically involves a sensory neuron, an interneuron, and a motor neuron, resulting in an automatic response to a stimulus.
2. Identify the components of a reflex arc: The key components include the receptor (which detects the stimulus), the sensory neuron (which transmits the signal to the central nervous system), the integration center (usually the spinal cord or brain), the motor neuron (which carries the signal away from the central nervous system), and the effector (which produces the response).
3. Define an unconditioned response: An unconditioned response is an automatic, involuntary reaction to a stimulus that does not require prior learning or conditioning. It is a natural response that occurs without conscious thought.
4. Analyze the examples given: 'Jumping at the sound of a loud noise' and 'Blinking in response to a bright light' are both reflexive actions, but they are not unconditioned responses in the context of a reflex arc. 'Salivating when food is placed in the mouth' is a classic example of an unconditioned response, as it is an innate reaction to the presence of food.
5. Conclude with the correct example: Based on the definition and analysis, 'Salivating when food is placed in the mouth' is the correct example of an unconditioned response in a reflex arc, as it is an automatic and natural reaction to the stimulus of food.