If an animal with a circadian clock of about 25 hours is kept in the dark without environmental time cues, it will
A) become active one hour earlier each day.
B) become active at the same time each day.
C) become active one hour later each day.
D) become active two hours earlier each day.
E) have an unpredictable pattern of activity.

Question

Quizplus · Accepted Answer

Without environmental cues, the animal's internal clock will run on its natural period of 25 hours, causing it to become active one hour later each day.

If an Animal with a Circadian Clock of About 25