What term describes the luminescence produced by physiological processes, such as in fireflies?

The term that describes the luminescence produced by physiological processes, such as in fireflies, is bioluminescence. This phenomenon occurs when living organisms, like fireflies, produce light through a biochemical reaction in their bodies, typically using a light-emitting molecule called luciferin and the enzyme luciferase.

Bioluminescence is distinct from other types of luminescence, such as fluorescence and phosphorescence, which do not involve biological processes. Fluorescence is the emission of light by a substance that has absorbed light or other electromagnetic radiation, but it only continues while the source of excitation is present. Phosphorescence, on the other hand, involves the absorption of light and the release of that energy over a longer time period, allowing a substance to glow even after the excitation source has been removed. In contrast, bioluminescence is an inherent capability of certain organisms to produce light as part of their metabolism, making it unique among the types of luminescence.