Which description best illustrates a negative feedback loop in homeostasis?

• A. A sensor detects deviation, effectors counteract it to return to set point, such as temperature regulation via sweating or shivering
• B. A hormonal signal amplifies the stimulus
• C. A system with no regulatory control
• D. A one-time response that does not adjust

Answer: (A)

Negative feedback loops in homeostasis work by sensing a change from the desired level and activating responses that push the system back toward that set point. In temperature regulation, sensors detect when body temperature deviates, and effectors like sweating or shivering act to restore normal temperature. This opposing action is what makes the description the best illustration of a negative feedback loop. The other ideas describe amplification (positive feedback), no regulatory control, or a one-time response that doesn’t adjust over time, none of which restore the system to the set point.