Is a neurotransmitter involved in the largely unconscious functioning of the autonomic nervous system (concerned with functions such as heart and respiration rate).

answer; atp and nadph;

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