Which of the following best distinguishes a negative feedback mechanism from a positive feedback mechanism in the human body?

• A. Both negative and positive feedback mechanisms always amplify changes in the body.
• B. Negative feedback amplifies a change, while positive feedback reverses a change to maintain homeostasis.
• C. Both negative and positive feedback mechanisms always reverse changes in the body.
• D. Negative feedback reverses a change to maintain homeostasis, while positive feedback amplifies a change.

Answer: (D)

Verified step by step guidance

1. Understand the concept of feedback mechanisms: Feedback mechanisms are processes that the body uses to maintain homeostasis. They can be categorized as negative feedback or positive feedback.
2. Define negative feedback: Negative feedback mechanisms work to reverse a change in the body to bring it back to a stable state. For example, if body temperature rises, negative feedback will activate processes to lower it back to normal.
3. Define positive feedback: Positive feedback mechanisms amplify or enhance a change in the body, moving it further away from the initial state. For example, during childbirth, the release of oxytocin increases uterine contractions, which further stimulates oxytocin release.
4. Compare the two mechanisms: Negative feedback is primarily involved in maintaining homeostasis by counteracting changes, while positive feedback is used in processes that require a rapid or amplified response, often for a specific purpose (e.g., blood clotting or childbirth).
5. Apply the definitions to the options provided: The correct answer is the one that accurately describes the roles of negative and positive feedback mechanisms—Negative feedback reverses a change to maintain homeostasis, while positive feedback amplifies a change.