External cues, such as the rising of the sun, used by animals to ...

[wenmo]

External cues, such as the rising of the sun, used by animals to establish daily rhythms are known as
 
  a. phase shifts.
 b. zeitgebers.
 c. entrainment signals.
 d. circadian rhythms.

Question 2

Which of the following is an example of a circadian rhythm?
 
  a. sleep-waking cycles
 b. menstrual cycles
 c. seasonal migration
 d. mating seasons

[krakiolit]

Answer to Question 1

b

Answer to Question 2

a

[wenmo]

Thanks for the timely response, appreciate it

[nguyenhoanhat]

TYSM