What term describes the maintenance of a stable internal environment in an organism?

The term that describes the maintenance of a stable internal environment in an organism is homeostasis. Homeostasis is a fundamental concept in biology that refers to the processes through which organisms regulate their internal conditions, such as temperature, pH, and other vital parameters, to maintain a stable and optimal state despite external changes. This regulation allows organisms to function effectively, as it ensures that their internal environment remains conducive to cellular activities and overall health.

For example, humans maintain a body temperature around 98.6°F (37°C) even when the external temperature varies widely. This self-regulating mechanism is crucial for survival and is achieved through various physiological responses such as sweating, shivering, and altering blood flow.

In contrast, equilibrium generally refers to a state of balance or equal distribution, which may not be specific to living organisms. Adaptation is a process by which organisms evolve over generations in response to their environments, while stability is a more general term that can apply to various systems, not necessarily linked to the biological processes of living organisms. Therefore, homeostasis is the precise term that encapsulates the concept of maintaining a stable internal environment in living beings.