What is negative feedback in homeostasis?

• A. A process that amplifies deviations from a set point.
• B. A process that maintains a constant deviation from a set point.
• C. A mechanism that overcorrects and overshoots the set point.
• D. A control mechanism that counteracts deviations from a set point to restore balance.

Answer: (D)

Negative feedback in homeostasis is a control process where a change from the normal set point triggers responses that oppose that change, bringing the system back toward the set point. Sensors detect the deviation, the system compares it to the set point, and effectors enact actions that reduce the error.

For example, if body temperature rises, mechanisms like sweating and vasodilation work to lose heat and cool the body. If temperature drops, shivering and vasoconstriction generate or conserve heat. In glucose regulation, rising blood sugar prompts insulin release to lower it back to normal.

This description captures the idea of counteracting deviations to restore balance. It’s different from processes that amplify changes, maintain a constant offset, or overshoot the set point, which align with other types of feedback or imperfect regulation.