circadian rhythm clock definition
A circadian rhythm /sÉËrËkeÉªdiÉn/ is any biological process that displays an endogenous, entrainable oscillation of about 24 hours. These 24-hour rhythms are driven by a circadian clock, and they have been widely observed in plants, animals, fungi, and cyanobacteria. The term circadian comes from the Latin circa, meaning around (or approximately), and diÄm, meaning day. The formal study of biological temporal rhythms, such as daily, tidal, weekly, seasonal, and annual rhythms, is called chronobiology.