AP BIOLOGY

Detailed explanation-1: -Any change in the environment to which an organism responds to is called a stimulus.

Detailed explanation-2: -A change in an organism’s surroundings that causes the organism to react is called a stimulus (plural stimuli). An organism reacts to a stimulus with a response-an action or change in behavior. Another example is if you are cold, you shiver. The cold is the stimulus while the shivering is the response.

Detailed explanation-3: -Answer and Explanation: A change in an organism’s environment that causes the organism to react is called a stimulus. A stimulus usually causes some kind of increase in activity, whether it’s metabolic or externally physical.