Stimulus and ResponseStimulus and Response

Why animals and plants do what they Why animals and plants do what they do do

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A fancy way of saying A fancy way of saying causecause and and effecteffect in the animal world. in the animal world.

CatalystCatalyst

1. Describe a situation in which you 1. Describe a situation in which you were immediately scared and/or were immediately scared and/or reacted quickly to something. Write reacted quickly to something. Write at least 1 paragraph with 4 at least 1 paragraph with 4 sentences describing your sentences describing your experience.experience.

2. Take out your journals and your 2. Take out your journals and your colors.colors.

After today you will be able After today you will be able to:to:

1. Identify and classify stimuli as 1. Identify and classify stimuli as internal or externalinternal or external

2. Define a response.2. Define a response.

3. Identify behavior as learned 3. Identify behavior as learned behavior or instinct.behavior or instinct.

What is a stimulus?What is a stimulus?

Stimulus:Stimulus: any change in an any change in an organism’s environment that organism’s environment that causes the organism to react. causes the organism to react. It It is a fancy way of saying “cause”.is a fancy way of saying “cause”.

StimulusStimulus – singular – singular StimuliStimuli – plural – plural

Example: An animal is cold so it moves into the sun.Example: An animal is cold so it moves into the sun.

(Add this word to your journal)(Add this word to your journal)

What is a response?What is a response?

Response:Response: how the organism how the organism reacts to a stimulus and results reacts to a stimulus and results in a change in behavior.in a change in behavior. ((It is a It is a fancy way of saying “effect”.)fancy way of saying “effect”.)

Example: Getting a drink when you are Example: Getting a drink when you are thirsty.thirsty.

(Add this word to your journal)(Add this word to your journal)

Examples of stimuli and their Examples of stimuli and their responses:responses:

• You are hungry so you eat some foodYou are hungry so you eat some food

• A rabbit gets scared so it runs awayA rabbit gets scared so it runs away

• You are cold so you put on a jacketYou are cold so you put on a jacket

• A dog is hot so lies in the shadeA dog is hot so lies in the shade

• It starts raining so you take out an It starts raining so you take out an umbrellaumbrella

Plants also respond to their Plants also respond to their environment. When a plant environment. When a plant grows towards the sun we call grows towards the sun we call this this phototropismphototropism..

Think – Pair - ShareThink – Pair - Share

Turn to your partner Turn to your partner and share two other and share two other stimuli and their stimuli and their responses. responses.

There are two types of There are two types of stimuli:stimuli:

External StimuliExternal Stimuli

andand

Internal StimuliInternal Stimuli

External StimulusExternal Stimulus

External stimulus: a stimulus that External stimulus: a stimulus that comes from outside an organism.comes from outside an organism.

Examples: Examples: 1. You feel cold so you put on a jacket.1. You feel cold so you put on a jacket.2. A snake lunges at a rabbit so it runs away.2. A snake lunges at a rabbit so it runs away.3. A dog feels hot so it goes to lay in the shade.3. A dog feels hot so it goes to lay in the shade.

Add this word to your journal.Add this word to your journal.

Internal StimulusInternal Stimulus

Internal stimulus:Internal stimulus: a stimulus that a stimulus that comes from inside an organism.comes from inside an organism.

Examples: Examples: 1. You feel hungry so you eat some food.1. You feel hungry so you eat some food.2. A cat feels thirsty so it drinks water.2. A cat feels thirsty so it drinks water.3. A dog feels hot so it goes to lay in the shade.3. A dog feels hot so it goes to lay in the shade.

Add this word to your journal.Add this word to your journal.

Make a T-chart in your journal and label the Make a T-chart in your journal and label the columns columns internalinternal and and externalexternal. Put the letter . Put the letter of each stimulus in the proper column. of each stimulus in the proper column.

A.A. You have a stomach ache and decide to You have a stomach ache and decide to lay down.lay down.

B.B. A bird is thirsty and drinks some water.A bird is thirsty and drinks some water.

C.C. A squirrel sees a cat and runs up a tree.A squirrel sees a cat and runs up a tree.

D.D. A lion gets hungry and eats a gazelle.A lion gets hungry and eats a gazelle.

E.E. You see a spider and scream.You see a spider and scream.

Animals can respond to stimuli Animals can respond to stimuli in two ways:in two ways:

1. In a way that they learned. We call 1. In a way that they learned. We call this this learned behavior.learned behavior.

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2. In a way that they were just born 2. In a way that they were just born knowing how to do. We call this knowing how to do. We call this instinct.instinct.

Learned behavior:Learned behavior: a a response to a response to a stimulus that an stimulus that an animal was taught.animal was taught.

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A mother bear teaching her A mother bear teaching her cubs to fishcubs to fish

Teaching an animal a trickTeaching an animal a trick

Training a dogTraining a dog

Even Even youyou have learned have learned behavior. For example, you behavior. For example, you learned to read and to talk.learned to read and to talk.

Instinct:Instinct: an animal’s an animal’s natural reaction to a natural reaction to a stimulus. It is an stimulus. It is an automatic reaction that automatic reaction that the animal was not the animal was not taught to do.taught to do.

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Animals natural instinct is to Animals natural instinct is to run away from danger. We call run away from danger. We call this the need for safety. this the need for safety.

Animals will naturally find or Animals will naturally find or make themselves a home make themselves a home because they have a need for because they have a need for shelter. shelter.

Animals will naturally look for Animals will naturally look for food and water. food and water.

Animals that need to will Animals that need to will naturally migrate. naturally migrate.

Animals instinctually know to Animals instinctually know to store their food for the winter.store their food for the winter.

Think – Write - ShareThink – Write - Share

In your journal write down one In your journal write down one learned behavior that you learned behavior that you have and one instinct that have and one instinct that you have.you have.

Summarize what you have learned today. Summarize what you have learned today.

1.1.What is a stimulus?What is a stimulus?2.2.What is a response?What is a response?3.3.Give one example of a Give one example of a

stimulus and its response.stimulus and its response.4.4.What is an internal stimulus?What is an internal stimulus?5.5.What is an external What is an external

stimulus?stimulus?

6.6. It is raining and you open up an It is raining and you open up an umbrella. Is this an internal or umbrella. Is this an internal or external response? Justify your external response? Justify your answer. answer.

7.7. What is an instinct?What is an instinct?8.8. When a rabbit runs away from a When a rabbit runs away from a

wolf is this learned behavior or wolf is this learned behavior or instinct? Justify your answerinstinct? Justify your answer..