Physiology. Biological clocks coordinately keep life on time.

Activity Cycles/genetics,physiology Adaptation, Physiological Animals Arabidopsis/genetics,physiology Biological Clocks/genetics,physiology Brain/physiology Cell Cycle/physiology Circadian Rhythm/genetics,physiology Cyanobacteria/cytology,physiology Feedback, Physiological Gene Expression Regulation Homeostasis Humans Light Mice Models, Biological Protein Biosynthesis Seasons Sleep Transcription, Genetic Yeasts/cytology,genetics,metabolism