What is the definition of homeostasis?

Homeostasis refers to the ability of an organism to maintain stable internal conditions despite changes in the external environment. This involves various physiological processes that regulate factors such as temperature, pH, hydration, and electrolyte balance within a narrow range essential for survival. For instance, humans maintain a core temperature around 37°C (98.6°F) through mechanisms like sweating or shivering, which respond to external temperature fluctuations.

In contrast, the other options describe different biological concepts. Generating energy is more related to metabolic processes rather than homeostasis. Reproduction and growth refer to the life cycle of organisms, encompassing their ability to produce offspring and develop from juvenile to adult forms. Adapting to external changes deals with how organisms evolve or adjust morphologically or behaviorally over time, which, while important, is distinct from the immediate regulation and maintenance of internal environments that homeostasis entails.