Positive feedback differs from negative feedback because:

• A. it decreases the response to a stimulus
• B. it amplifies the original stimulus rather than reversing it
• C. it always maintains homeostasis
• D. it is more common in the body than negative feedback

Answer: (B)

Verified step by step guidance

1. Understand the concept of feedback mechanisms: Feedback mechanisms are processes that help regulate physiological functions in the body. They are categorized into negative feedback and positive feedback.
2. Define negative feedback: Negative feedback works to reverse a change in a physiological condition, bringing the system back to its set point or maintaining homeostasis. For example, the regulation of body temperature or blood glucose levels.
3. Define positive feedback: Positive feedback amplifies or enhances the original stimulus, pushing the system further away from its set point. It is less common in the body and typically occurs in specific scenarios, such as childbirth (oxytocin release during labor) or blood clotting.
4. Compare the two mechanisms: Negative feedback is more common and works to maintain homeostasis by counteracting changes, while positive feedback amplifies changes and is not primarily focused on maintaining homeostasis.
5. Analyze the options provided: The correct answer is that positive feedback amplifies the original stimulus rather than reversing it, as this is the defining characteristic of positive feedback mechanisms.