Final answer:
The maintenance of a stable internal environment by living organisms is known as homeostasis, which involves feedback mechanisms to respond to changes both internally and externally.
Step-by-step explanation:
Living organisms maintain a constant internal environment by sensing and responding to their internal conditions. This stable maintenance of internal conditions is known as homeostasis. For example, human beings maintain a stable internal body temperature. When exposed to cold environments, the body doesn't freeze; instead, through mechanisms like shivering, it works to maintain that stable temperature regardless of external conditions.
Organisms use feedback mechanisms to keep their internal environments stable and to react to changes in their external environment. These processes are essential for survival and play a crucial role in the overall function of biological systems.