AP PSYCHOLOGY

Detailed explanation-1: -The circadian clock has an internally driven 24-hour rhythm that tends to run longer than 24 hours but resets every day by the sun’s light/dark cycle. Taking melatonina supplements can also shift the timing of the body’s “clock.”

Detailed explanation-2: -Regulation of circadian period in humans was thought to differ from that of other species, with the period of the activity rhythm reported to range from 13 to 65 hours (median 25.2 hours) and the period of the body temperature rhythm reported to average 25 hours in adulthood, and to shorten with age.

Detailed explanation-3: -Circadian rhythms are physical, mental, and behavioral changes that follow a 24-hour cycle. These natural processes respond primarily to light and dark and affect most living things, including animals, plants, and microbes. Chronobiology is the study of circadian rhythms.

Detailed explanation-4: -Normal people have a circadian rhythm that is slightly longer than 24 hours. Every day, morning light and other behaviors reset the sleep-wake clock to a 24-hour schedule. Without light and this clock resetting, people’s sleep time will drift later and later.

Detailed explanation-5: -To stay on the 24-hour cycle, the brain needs the input of sunlight through the eyes to reset itself each day. When humans are allowed to run off their body’s clock apart from input from the sun, by being kept in continuous darkness, the body’s daily cycle tends to lengthen to about 25 hours.