46. Which of the following statements about circadian rhythm is FALSE?
(A) Circadian rhythm is an intrinsic biological clock that can be synchronized by external
day/night cycles.
(B) Cyclic alterations of human body temperature also reflect circadian rhythm.
(C) If an organism is kept in a constant environment, such as continuous light, its circadian
rhythm will remain precisely 24 hours.
(D) Melatonin secretion also follows circadian rhythm, with its concentration peak occurring
around 4:00 AM.
(E) Both phytochromes and blue light photoreceptors can entrain circadian rhythm in plants.