One of the signs that sleep is necessary is that all living creatures
a. are harmed by lack of sleep
b. can put off sleep for a time
c. avoid sleep as much as possible
d. can sleep longer than necessary select the best answer from the choices provided a b c d

One of the signs that sleep is necessary is that all living creatures are harmed by lack of sleep. Correct A Sleep serves important evolutionary functions for all animals, because sleep helps animals consolidate memories and learn. Animals sleep according to how much they eat – animals that eat food with a lower caloric density sleep less than others. However, lack of sleep and if the deprivation is long enough it can kill animals.

steady state because it the only on that maes sense