Our tendency to feel wakeful and sleepy on a 24-hour basis depends mainly on
a. a cycle generated by a mechanism in the brain
b. our perception of environmental stimuli such as heat and light
c. a cycle generated by hormone-producing organs such as the adrenal gland
d. wear and tear on the muscles followed by a period of repair
I chose answer A. because humans have mechanisms that prepare us for activity during the day and sleep at night. But the other choices seem to somewhat fit...Is this answer correct?
1 answer
I agree that A is the best answer. However, we can modify the brain mechanism by external stimuli.