Your friend asks,"Why am I this way? I mean,why do I like to get up early in the morning? I get really tired in the afternoon." The reason for your friend's preference and energy in the morning is:
A) high levels of melatonin in the morning
B) the level of activity in the suprachiasmatic nucleus
C) she is experiencing the effects of jet lag
D) she has abnormally high levels of non-REM

Question

Quizplus · Accepted Answer

The suprachiasmatic nucleus (SCN) is responsible for regulating the body's circadian rhythm and is active during the day. This leads to increased alertness and energy in the morning and decreased energy in the afternoon. Melatonin, a hormone that regulates sleep, is low in the morning and increases at night. Jet lag refers to a disruption in circadian rhythm due to travel across time zones. Abnormally high levels of non-REM sleep would not necessarily explain why someone prefers to wake up early in the morning.

Your Friend Asks,"Why Am I This Way? I Mean,why Do