Which is an example of an animal responding to an external stimulus? A. A dog growing a winter coat

B. A cat drinking milk

C. A mouse eating food

D. A person sleeping

A. A dog growing a winter coat

Explanation:

Animal Responses to External Stimuli

Animals must react to changes in their external environment to survive. If a reaction is immediate and involuntary, the response is called a reflex reaction. Blinking the eyes in response to sunlight is an example of a reflex reaction.

dna is made up of six smaller molecules -- a five carbon sugar called deoxyribose, a phosphate molecule and four different nitrogenous bases (adenine, thymine, cytosine and guanine).