1. Stimulus and Response Why animals and plants do what they do OR
A fancy way of saying cause and effect in the animal world.

2.
Describe a situation in which you were immediately scared and/or reacted quickly to something. Write at least 1 complete sentence describing your experience in your spiral.

3. What is a stimulus?
any change in an organism’s environment that causes to the organism to react. It is a fancy way of saying “cause”.
Example: An animal is cold so it moves into the
sun.
Example: Getting a drink when you are thirsty.

4. What is a response?
how the organism reacts to a stimulus and results in a change in behavior. It is a fancy way of saying “effect”.
Example: An animal is cold so it moves into
the sun.
Example: Getting a drink when you are thirsty.

5. Examples of stimuli and their responses:
Circle the stimulus and underline the response:
You are hungry so you eat some food
On your own, complete the rest of question 4

6. Plants also respond to their environment. They are called tropisms
gravitropism
phototropism
thigmotropism

7. There are two types of stimuli:
External Stimuli
and
Internal Stimuli

8. External Stimulus a stimulus that comes from outside an organism.
Examples:
1. You feel cold so you put on a jacket.
2. A snake lunges at a rabbit so it runs
away.
3. It is a very hot, sunny day so a dog sits
in the shade.

9. Internal Stimulus a stimulus that comes from inside an organism.
Examples:
1. You feel hungry so you eat some food.
2. A cat feels thirsty so it drinks water.
3. A dog feels sick so it’s body triggers a
fever.

10. Animals can respond to stimuli in two ways:
1. In a way that they learned. We call this learned behavior. OR
2. In a way that they were just born knowing how to do. We call this instinct.

11. Learned behavior: a response to a stimulus that an animal was taught.
Examples: chimps bear teaching her
and monkeys cubs to fish
learning to use
tools

12. Learned behavior: Pavlov’s Dog
Famous dog experiment done by Ivan Pavlov
ring a bell
feed dog
dog salivates
over time, the dog will
salivate when it hears
the bell.

13. Instinct:
an animal’s natural reaction to a stimulus. It is an automatic reaction that the animal was not taught to do.
Examples: finding or building a shelter
Examples: getting away from danger

14. Homeostasis
An organisms response to internal and external stimuli helps to maintain homeostasis
Homeostasis – balance or equilibrium inside a living organism
Blood sugar levels
Sweating/shivering
Fever
Vomiting
Plant tropisms

15. Blood Glucose Levels
In order to maintain homeostasis, your body tries to keep a certain blood glucose level
When blood glucose is low, you should eat
When blood glucose is high, your pancreas should release insulin
Problems with this system can create diabetes

16. Pill Bugs http://youtu.be/p97-JHO-RNM
After watching the pill bug demonstration, complete the activity.