When she participated in a sleep experiment, Yvette lived in an isolation unit for one month without any external time cues. It is very probable that her internal body clock drifted to the natural or intrinsic rhythm of approximately:
A) 28 days.
B) 25.2 hours.
C) 22.4 hours.
D) 24.2 hours.

Question

Quizplus · Accepted Answer

The internal body clock of a human being naturally operates on a cycle that is slightly longer than 24 hours. Research shows that the intrinsic period of the human circadian rhythm is between 24.18 and 24.25 hours. Therefore, it is most likely that Yvette's internal body clock drifted to a natural rhythm of approximately 24.2 hours during her one-month isolation period.

When She Participated in a Sleep Experiment, Yvette Lived in an Isolation