Question

anything that causes change, or activity in an organism is a stimulus (plural: stimuli). stimuli come from both inside and outside of an organism. the change or activity caused by a stimulus is a response. a stimulus is like a message. a response is like an answer to the message. each picture shows a stimulus and response. what are the stimulus and response shown in each picture? write your answers on the lines under each picture. figure a stimulus response figure b stimulus response these three pictures show how the pupils of the eyes react to light. light is a stimulus. the top picture shows how your pupil might look in a dark room. the bottom picture shows how your pupil might look in bright light. the middle picture shows the eye in normal light. 1. in bright light, what happens to the size of your pupils? 2. in dim light, what happens to the pupil size? 3. how do you think this reaction by the pupil helps a person?

Explanation:

In Figure A, sunlight is the stimulus that causes the plant to grow towards it (phototropism). In Figure B, the tickling is the stimulus and the child's laughter is the response. For the eye - related questions: In bright light, the pupils constrict to reduce the amount of light entering the eye. In dim light, the pupils dilate to allow more light in. This reaction helps protect the eye from over - exposure to light in bright conditions and improves vision in low - light conditions by letting in more light.

Answer:

Figure A:
Stimulus: Sunlight
Response: Plant growing towards the light

Figure B:
Stimulus: Tickling
Response: Child laughing

1. In bright light, the size of the pupils decreases (constricts).
2. In dim light, the pupil size increases (dilates).
3. This reaction helps protect the eye from excessive light in bright conditions and improves vision in low - light conditions by allowing more light to enter the eye.