When a person is shut off from the world, such that he or she cannot even tell what time it is by light or dark for several days, this person's sleep-waking cycle will
A)stay exactly as it was since this cycle is innate and cannot be modified.
B)shorten to an average of about 20 hours.
C)lengthen to about 25 hours.
D)become completely disrupted.

Question

Quizplus · Accepted Answer

This phenomenon is known as the free-running sleep-wake cycle. Without any external time cues, our bodies tend to operate on a slightly longer cycle than 24 hours. The average free-running cycle is around 25 hours, meaning that the person's sleep-wake cycle will gradually shift later and later each day.

When a Person Is Shut Off from the World, Such