What term defines varieties or populations of human beings distinguished by physical traits such as hair, eyes, skin color, and body shape?
a. class
b. cohort
c. ethnicity
d. race

i was thinking 4.0 v hope this

stimulus is a change in the environment that causes an organism to react. the response is the reaction to the stimulus. some examples of stimuli for zebras are drought, to many predators, and bad feeding grounds such as dead grass or plants. zebras respond to stimuli just like all other living organisms