What is homeostasis?

Homeostasis refers to the ability of an organism to maintain stable internal conditions despite changes in the external environment. This concept is fundamental in biology because it describes how living organisms regulate their internal environment to ensure optimal functioning. For instance, humans and many other animals maintain their body temperature, pH levels, and hydration status within a narrow range that is essential for survival.

To achieve homeostasis, organisms may use various physiological processes, such as thermoregulation (maintaining body temperature), osmoregulation (regulating water and solute concentrations), and blood glucose regulation. These processes involve feedback mechanisms that detect changes in the internal environment and trigger responses that restore balance.

The other options, while relating to biological concepts, do not accurately define homeostasis. Adapting to new environments is more about evolutionary changes rather than the immediate regulatory processes of an organism, growth pertains to developmental changes over time, and extinction involves the complete loss of a species due to factors affecting their survival. Hence, maintaining stable internal conditions is the hallmark of homeostasis.