When Alexandra flew to Australia to begin her semester abroad, she was on a plane for more than 20 hr. She didn't sleep the day before her trip because she was too excited, she didn't sleep on the plane because it was too uncomfortable, and she didn't sleep the day she arrived because she didn't want to miss a moment. When it was finally time to sleep, Alexandra was wide awake because her ______ was disrupted.
A) biological clock
B) epigenetic clock
C) circadian rhythm
D) epigenetic rhthym

Question

Quizplus · Accepted Answer

Alexandra's sleep pattern was disrupted because of the change in time zones, which disturbs the circadian rhythm, also known as the sleep-wake cycle. The biological clock is another term for the circadian rhythm, so option A is partially correct but not the best choice. The epigenetic clock and rhythm have to do with changes in gene expression over time and are not relevant to this situation.

When Alexandra Flew to Australia to Begin Her Semester Abroad