Which of the following best describes homeostasis?

Homeostasis refers to the dynamic process through which living organisms maintain stable internal conditions despite fluctuations in the external environment. This concept is crucial for the survival of organisms, as it involves the regulation of various physiological parameters such as temperature, pH, hydration levels, and electrolyte concentrations.

For example, mammals maintain a relatively constant body temperature through mechanisms such as sweating, shivering, and adjusting blood flow to the skin. Such regulatory processes ensure that cells function optimally, which is vital for overall health and survival. The ability to maintain homeostasis is a hallmark of living organisms, allowing them to thrive in diverse conditions.

The other options pertain to different biological concepts. The ability to develop new characteristics relates to evolution and genetic changes over time. Adapting to new environments discusses how species can change behaviorally or physically to survive in different conditions, but that is not the same as maintaining internal stability. Finally, variation in a species over time refers to evolutionary processes that lead to changes within a population, which is also distinct from the concept of homeostasis.