Question

an environmental \boxed{} that causes an organism to change its activity is called a \boxed{}. organisms maintain their \boxed{} by responding to stimuli. the way an organism reacts to the stimulus is called a \boxed{}. some changes occur inside an organism. these are \boxed{} stimuli. others take place outside, which are \boxed{} stimuli. \boxed{} is an internal stimulus. when a person is thirsty, he or she will drink \boxed{}, which helps replace the lost water and also helps maintain proper water balance. external stimuli affect the growth of many \boxed{} that respond to \boxed{}. sunflower plants turn their flowers toward the sun as it moves across the sky.

Explanation:

This is a fill-in-the-blank exercise about organism responses to stimuli, based on basic biological concepts of homeostasis and stimulus-response mechanisms. The terms provided are matched to their correct definitions and examples:

1. An environmental factor triggering activity change is a stimulus.
2. The general term for this trigger category is stimulus.
3. Organisms maintain stability (homeostasis) via responses.
4. The reaction to a stimulus is a response.
5. Stimuli from inside an organism are internal.
6. Stimuli from outside an organism are external.
7. Thirst is an internal stimulus from dehydration.
8. Drinking water responds to thirst to balance fluids.
9. External stimuli affect plant growth.
10. Plants like sunflowers respond to light (sunlight).

Answer:

1. stimulus
2. stimulus
3. homeostasis
4. response
5. internal
6. external
7. Thirst
8. water
9. plants
10. sunlight