What is the major difference between positive and negative feedback in biological systems?

• A. Positive feedback is only found in plants, while negative feedback is only found in animals.
• B. Positive feedback amplifies a change in a system, while negative feedback counteracts or reduces the change.
• C. Both positive and negative feedback always stabilize biological systems.
• D. Negative feedback amplifies a change in a system, while positive feedback counteracts the change.

Answer: (B)

Verified step by step guidance

1. Step 1: Begin by understanding the concept of feedback mechanisms in biological systems. Feedback mechanisms are processes that help maintain homeostasis by regulating physiological functions in response to changes in the environment.
2. Step 2: Define positive feedback. Positive feedback amplifies or increases the effect of a change in a system. It drives the system further away from its initial state, often leading to a specific outcome. For example, during childbirth, the release of oxytocin intensifies uterine contractions, which further stimulates oxytocin release.
3. Step 3: Define negative feedback. Negative feedback counteracts or reduces the effect of a change in a system. It helps restore the system to its original state or maintain stability. For example, the regulation of blood glucose levels involves insulin and glucagon working to stabilize glucose concentration.
4. Step 4: Compare the two mechanisms. Positive feedback amplifies changes and is typically involved in processes that need a definitive outcome, while negative feedback reduces changes and is crucial for maintaining homeostasis and stability in biological systems.
5. Step 5: Address the incorrect statements in the problem. Positive feedback is not exclusive to plants, nor is negative feedback exclusive to animals. Both mechanisms do not always stabilize biological systems; positive feedback often leads to a specific endpoint rather than stabilization.