Question

Xiao finds that she feels least alert during the day around 3 p.m., and she does her best work before noon every day. This is most likely because her circadian rhythm causes her cortisol to be:

a) Higher in the morning before noon
b) Lower in the morning before noon
c) Absent
d) Peaking in the afternoon around 3 p.m.

Answer 1

Xiao feels most alert before noon due to higher cortisol levels in the morning, which is a result of her circadian rhythm.

Step-by-step explanation:

Xiao's experience of feeling most alert before noon and least alert around 3 p.m. is likely related to her circadian rhythm, which regulates the secretion of various hormones, including cortisol. Cortisol is one of the cortical hormones whose levels peak in the morning, helping to promote alertness and wakefulness after the onset of sleep. Therefore, the correct answer is that Xiao's cortisol levels are a) Higher in the morning before noon. As the day progresses, these cortisol levels typically decrease, leading to reduced alertness during the afternoon.