A biological clock is an internal mechanism that regulates the timing of various physiological processes in living organisms. It helps control cycles such as sleep-wake patterns, hormone release, and metabolism. These rhythms, known as circadian rhythms, typically follow a 24-hour cycle and are influenced by external cues like light and temperature. Biological clocks are found in many organisms, including humans, animals, and plants. In humans, the suprachiasmatic nucleus (SCN) in the brain plays a crucial role in maintaining these rhythms. Disruptions to the biological clock can lead to issues like sleep disorders and other health problems.