Which term refers to the tendency of a biological system to maintain internal stability while adjusting to changing external conditions?

• A. Nutrient Requirements
• B. Homeostasis
• C. Zoonosis
• D. Graduated Cylinder

Answer: (B)

Maintaining internal stability while external conditions change is homeostasis. This concept describes how an organism regulates processes such as temperature, pH, and nutrient levels to keep conditions inside the body within a narrow, optimal range, even as the outside environment shifts. When conditions move away from the ideal, the body activates responses to counteract the change and keep systems functioning properly—for example, cooling itself via sweating when hot or conserving heat through shivering when cold. Nutrient requirements refer to the amounts of nutrients an organism needs, which is different from the regulatory balance described by homeostasis. Zoonosis is about disease transmission between animals and humans, and a graduated cylinder is simply a tool for measuring liquids. Therefore, the best term for this tendency is homeostasis.