Unit 10

Homeostasis

My GoalsI will know what homeostasis

means.

I will explain the difference between a stimulus and a response.

1. Find your heart beat on your neck or wrist.

2. Count the number of times your heart beats in 30 seconds.

3. Write this number down on the table under “At Rest”.

1. Run in place for 30 seconds. (FAST)

2. Find your heartbeat in your neck/wrist. Count the number of times your heart beats in

30 seconds.

3. Write this number under “After Running”

**When you are more active, you burn more energy. When your cells burn energy, they

create waste (carbon dioxide).

Breathing faster!

How do you get rid of this extra carbon dioxide from your blood?

Think, Pair, Share

With your partner, brainstorm the meaning of the following words.

1. Balance2. External3. Internal4. Respond5. Environment6. Maintain

Key Concept 1:

Organisms respond to changes in the external environment in order to maintain balance.

We call this balance homeostasis.

Create a Gesture for: Homeostasis

Organisms respond to changes in the external environment in order to maintain balance, this balance is called homeostasis.

TPS: What is happening in this picture?

The change in the external environment is called a stimulus, and the resulting reaction of the organisms is called a response.

Stimulus & Response

What is the stimulus in this picture?

What is the cat’s response in this picture? Santa is the stimulus!

The cat scratching and hissing is the response!

Organisms have responses to:

internal changes and

external stimuli

Stimulus & Response

Does a plant respond to a stimulus?

1. Which celery stalk has more turgor pressure? 2.

What causes turgor pressure?

Think, Pair, Share

With your partner, brainstorm the meaning of the following words.

1. Geotropism2. Gravity3. Photosynthesis4. Phototropism5. Negative6. Positive

Which plant is in a state of homeostasis?

How do plants respond to stimuli?

Geotropism is a plant’s response to gravity.

Which way are the roots growing? Why?

Roots grow down (towards gravity’s pull) = Positive Response to Gravity

Leaves and Stem grow upwards (away from gravity) = Negative Response to Gravity

What is the stimulus in geotropism?

Gravity is the stimulus!

You say it!

Towards the stimulus = Positive Response

Away from the stimulus =

Negative Response

What is phototropism?

Phototropism is a plant’s response to light.

What are tropisms?

Tropism = plant’s response towards/away from a stimulus

(sun or gravity)

What are 2 stimuli that plants respond

to? Phototropism is a plant’s response to light.

Geotropism is a plant’s response to gravity.

What is Homeostasis?

Frank the Squirrel

Frank the squirrel has mad basketball skills.

1. When he gets hot during a basketball game, he perspires. Why does he sweat?

2. What is the stimulus to sweating?

Quiz Time!

What is the stimulus in this situation?

What is the response in this situation?

Which animal is in a state of homeostasis?

What is the stimulus in this photo?

What is the response in this photo?

What word is described with these photos?

_ _ _ _ _ _ _ _ _ _ _ _ _ _

What word is described with these photos?

_ _ _ _ _ _ _ _ _ _ _

Which human is in a state of homeostasis?

1. How do you feel when your body is in a state of homeostasis?

or…..

1. What words can you use to describe how you feel when you are in homeostasis?

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