10 questions
A young girl jumps back in fear from a loud, unexpected noise nearby
Response to an external stimulus
Response to an internal stimulus
A worm begins to coil up and wriggle around when it is touched
Response to an external stimulus
Response to an internal stimulus
A dog vomits because of a bacterial infection from food poisoning
Response to an external stimulus
Response to an internal stimulus
The pupils of the eye constrict when exposed to bright light
Response to an external stimulus
Response to an internal stimulus
When a boy's blood sugar levels increase, his pancreas releases insulin into the bloodstream
Response to an external stimulus
Response to an internal stimulus
A man’s body temperature increases when he’s infected with the flu virus
Response to an external stimulus
Response to an internal stimulus
A boy is being chased by two mean dogs, which triggers the fight-or-flight response
Response to an external stimulus
Response to an internal stimulus
A soccer player starts sweating when her body temperature increases
Response to an external stimulus
Response to an internal stimulus
A fish sees shadows moving above the water and swims away to safety
Response to an external stimulus
Response to an internal stimulus
A person's blood volume is too low from dehydration, so the brain releases a hormone into the bloodstream to reduce urine production
Response to an external stimulus
Response to an internal stimulus