What does homeostasis refer to in biological systems?

Homeostasis refers to the process by which biological systems maintain stable internal conditions despite changes in the external environment. This involves a variety of mechanisms that regulate aspects like temperature, pH, hydration, and nutrient levels, ensuring that cells and organisms can function optimally. For instance, in humans, homeostasis is crucial for regulating body temperature through mechanisms like sweating or shivering, depending on external temperatures. This ability to maintain equilibrium is essential for life, as significant deviations from these stable internal conditions can disrupt cellular functions and ultimately threaten an organism’s survival.

The other choices do not accurately encompass the concept of homeostasis. The process of cell division pertains more to growth and reproduction, while the physical structure of cells relates to their morphology and does not address internal stability. Lastly, although growth and reproduction are fundamental biological processes, they do not directly involve the maintenance of internal conditions.