Which of the following is true regarding positive and negative feedback in biological systems?

• A. Negative feedback amplifies the initial stimulus.
• B. Positive feedback always restores the system to its original state.
• C. Negative feedback maintains homeostasis by counteracting changes from a set point.
• D. Positive feedback is more common than negative feedback in maintaining homeostasis.

Answer: (C)

Verified step by step guidance

1. Understand the concept of feedback mechanisms in biological systems: Feedback mechanisms are processes that regulate biological systems to maintain stability or amplify changes. They are categorized as positive feedback and negative feedback.
2. Clarify negative feedback: Negative feedback works to counteract changes from a set point, helping to maintain homeostasis. For example, when body temperature rises, mechanisms like sweating are activated to cool the body down, restoring the temperature to its normal range.
3. Clarify positive feedback: Positive feedback amplifies the initial stimulus rather than counteracting it. It is less common in maintaining homeostasis and is typically involved in processes that need a rapid or decisive outcome, such as blood clotting or childbirth contractions.
4. Evaluate the statements provided: Negative feedback does not amplify the initial stimulus; it counteracts changes to maintain homeostasis. Positive feedback does not restore the system to its original state; it amplifies changes. Negative feedback is more common than positive feedback in maintaining homeostasis.
5. Conclude the correct answer: Based on the explanations above, the correct statement is: 'Negative feedback maintains homeostasis by counteracting changes from a set point.'