AP BIOLOGY

Detailed explanation-1: -Stimulus is of two types, external and internal. Smell, sound, etc., are examples of external stimuli and hunger, thirst, etc., are examples of internal stimuli.

Detailed explanation-2: -Internal stimulus For example one of the internal stimuli is hunger which is the sign of low energy in the body. It stimulates us to eat something to regain the needed energy.

Detailed explanation-3: -Stimuli can be external or internal. An example of external stimuli is your body responding to a medicine. An example of internal stimuli is your vital signs changing due to a change in the body.

Detailed explanation-4: -The digestive system can respond to external stimuli, such as the sight or smell of food, and cause physiological changes before the food ever enters the body.

Detailed explanation-5: -Examples of internal stimulus include hunger, thirst, and emotional states.