1. What starting population sizes of grasshoppers, frogs, and hawks produced a balanced food chain (at least 2 grasshoppers, 2 frogs, and 1 hawk)? What was the problem with having equal numbers of frogs, grasshoppers, and hawks? Per 2

Per. 3

Start Finish

Round 1

9 grasshoppers 2 grasshoppers

9 frogs 0 frog

9 hawks 2 hawks

Round 2

12 grasshoppers 0 grasshoppers

11 frogs 1 frogs

4 hawks 2 hawks

Round 3

14 grasshoppers 1 grasshoppers

11 frogs 4 frogs

2 hawks 1 hawks

1. What starting population sizes of grasshoppers, frogs, and hawks produced a balanced food chain (at least 2 grasshoppers, 2 frogs, and 1 hawk)? What was the problem with having equal numbers of frogs, grasshoppers, and hawks? Per 3

Per. 3

Start Finish

Round 1

9 grasshoppers 6 grasshoppers

9 frogs 0 frog

8 hawks 0 hawks

Round 2

12 grasshoppers 5 grasshoppers

10 frogs 0 frogs

4 hawks 1 hawks

Round 3

12 grasshoppers 5 grasshoppers

10 frogs 1 frogs

4 hawks 0 hawks

1. What starting population sizes of grasshoppers, frogs, and hawks produced a balanced food chain (at least 2 grasshoppers, 2 frogs, and 1 hawk)? What was the problem with having equal numbers of frogs, grasshoppers, and hawks? Per 4

Per. 3

Start Finish

Round 1

10 Grasshoppers 3 grasshoppers

9 frogs 0 frog

9 hawks 1 hawks

Round 2

13 grasshoppers 5 grasshoppers

11 frogs 0 frogs

4 hawks 2 hawks

Round 3

13 grasshoppers 2 grasshoppers

11 frogs 4 frogs

4 hawks 2 hawks

1. What starting population sizes of grasshoppers, frogs, and hawks produced a balanced food chain (at least 2 grasshoppers, 2 frogs, and 1 hawk)? What was the problem with having equal numbers of frogs, grasshoppers, and hawks? Per 1

Per. 3

Start Finish

Round 1

9 grasshoppers 1 grasshoppers

8 frogs 0 frog

8 hawks 5 hawks

Round 2

10 Grasshoppers 1 grasshoppers

10 frogs 0 frogs

5 hawks 5 hawks

Round 3

11 grasshoppers 6 grasshoppers

12 frogs 2 frogs

2 hawks 1 hawks

Ecological Pyramid

In order to have balanced food chain, must have more organisms at bottom of chain than at top or there wont’ be enough food for everyone.

2. Describe what effects the disappearance of frogs would be likely to have on the populations of grasshoppers and plants. Explain your reasoning.

• Grasshopper population probably increase because no frogs eating them.

• Plant population probably decrease because more grasshoppers eating them.

3. Suppose the leaves marked with black “X’s” contained poison. Does the concentration of poison increase or decrease as you go up the food chain? Why?

• Increase

grasshoppers

grasshoppers

frog

hawk

3. Suppose the leaves marked with black “X’s” contained poison. Does the concentration of poison increase or decrease as you go up the food chain? Why?• Increase• Each animal eats many animals from the feeding level below it, so

there’s more and more poison taken in as you go up the food chain.

grasshoppers

hawk

frogs

What commonly eaten animal in Puget Sound is considered unsafe to eat more than once a week for this reason?

Salmon is considered unsafe to eat more than once a week because….

• Mercury is a toxic pollutant in coastal seas.

• Concentration of mercury increases as it moves up the food chain.

4. How did this simulation demonstrate the concepts of interconnections and interdependence in nature?

• Everything is connected in nature through food chains and food webs.

• What affects one part of the web affects all the others directly or indirectly.

5. In what ways was our simulation realistic? Unrealistic? How could we make it more realistic?

• Real animals, real food chain.• Real struggle to survive.

• Real animals have more than one food source.• Real animals can hide.

• Allow animals to hide.• Add other predators, prey.