Circadian Rhythms

A circadian rhythm is a 24-hour cycle in the biochemical, physiological, or behavioral processes of living entities, including plants, animals, fungi and bacteria. The term "circadian" comes from the Latin circa, "around", and diem or dies, "day", literally meaning "approximately one day". The formal study of biological temporal rhythms such as daily, tidal, weekly, seasonal, and annual rhythms, is called chronobiology.