What term describes maintaining a relatively stable internal environment?

• A. Regulation
• B. Equilibrium
• C. Homeostasis
• D. Stability

Answer: (C)

Maintaining a relatively stable internal environment is homeostasis. This concept describes how organisms keep conditions such as temperature, pH, glucose levels, and fluid balance within a narrow range, even when the outside environment changes. It relies on sensors that detect deviations, regulatory processes (often in the brain and organs) that compare signals to a set point, and effectors that bring conditions back toward that set point through negative feedback. For example, when body temperature rises, the body cools itself through sweating and increased blood flow to the skin; when it drops, it conserves or generates heat through shivering and reduced blood flow. While Regulation is a related idea, homeostasis names the specific process of maintaining internal stability. Equilibrium would imply no net change and no energy use, which isn’t how living systems operate. Stability alone is too vague to capture the regulating mechanisms at work.