Many cellular events happen at specific times of the day. Day–night (light– darkness) alternation has trained organisms1 to anticipate periodic environmental changes and organize metabolism and behavior accordingly. Biological daily clocks coordinate the activity of the body’s organs and tissues. Many mammalian cells contain a molecular clock, i.e., a set of genes of which the cyclical expression controls self-sustained oscillators that are reset every day. The clock can keep ticking after the removal of all external stimuli.
KeywordsCircadian Rhythm Circadian Clock Clock Gene Suprachiasmatic Nucleus Circadian Clock Gene
Unable to display preview. Download preview PDF.