Answer Key to Life Zones Task

The target level for each question refers to a level on either the Natural Resources & Human Impact, Patterns or the Argumentation learning progression.

Correct answers are underlined.

The picture below shows Frog Mountain. A wide range of plant species can be found on the mountain.

Target level:  Natural resources & human impact level 1 

1. What is the source of water for the plants on the mountain?

a. Rain

b. Air

c. Forest

d. There is not enough information.

Target level: Patterns level 3

2.  How is the plant community at the top of the mountain different from the plant community at the bottom of the mountain?

a. At the top there are large trees, at the bottom there are cactuses. 

b. The top is greener and the bottom is browner. 

c. There are no plants at the bottom of the mountain. 

d. There is more water at the top than the bottom. 

Target level: Patterns level 3

3. Using the diagram above, describe how the plant community changes with elevation.

a. As elevation increases, the plant community becomes more green and there are fewer smaller plants.

b. As elevation decreases, the plant community changes from more healthy to less healthy.

c. As elevation decreases, the plant community changes from large plants to small plants.

d. As elevation increases, the plant community changes from plants that need less water  to plants that need more water.

Target level: Patterns level 2

4. What is the relationship between elevation and climate? Select the correct options below.

As elevation increases, temperature #increases | decreases | stays the same# and rainfall #increases | decreases | stays the same#.

Target level: Natural resources & human impact level 2

5. Why is the desert plant community only at the bottom of the mountain?

a. Desert plant communities grow at low elevations.

b. Desert plant communities grow only where there is little water.

c. Desert plant communities grow only where temperatures are hot.

d. Desert plant communities grow where there are fewer clouds.

Target level: Patterns level 2

6. How is the bottom of the mountain similar to the top of the mountain?

a. Both have plants.

b. Both have trees.

c. Neither have any rainfall.

d. The bottom of the mountain is cold and the top is hot.

The pictures below show Frog Mountain in Arizona compared to Mt. Kimball, which is about the same height as Frog Mountain but it is in Alaska.

Two students are having a disagreement about why they see certain patterns of plants on each of the mountains.

Anna says: "Rainfall is the most important factor that determines the plant species that can grow at a particular elevation on a mountain."

Sara says: "Temperature is the most important factor that determines the plant species that can grow at a particular elevation on a mountain."

Target level: Argumentation level 2a 

7. Which piece of evidence supports Sara?

a. No plants can live at the top of Mt. Kimball.

b. As the elevation of a mountain increases, rainfall increases.

c. It is very wet at the top of both Frog Mountain and Mt. Kimball.

d. As the elevation of a mountain increases, temperature decreases.

Target level: Argumentation level 2a 

8. Sara constructs an argument that temperature is the most important. What does she say?

Select the correct options in the last sentence:

Sara says:

"Temperature is the most important factor that determines the plant species that can grow at a particular elevation on a mountain. At the top of Frog Mountain it is cold (30 degrees Fahrenheit) and wet (2 ft of rain per year). At the bottom of Mt. Kimball, it is also cold (30 degrees Fahrenheit), but it does not get very much rain (6 inches per year). On Frog Mountain, there is a forest ecosystem at the top of the mountain and on Mt. Kimball, there is a forest ecosystem at the bottom of the mountain. At the top of Mt. Kimball the temperature is very, very cold and no plants can live there.

Because the plants growing on top of each mountain are #the same | different#, and the temperatures on the tops of each mountains are #the same | different#, we can conclude that temperature is #important | not important# for determining which types of plants can live at each elevation."

Target level: Argumentation level 2a 

9. Sara constructs an argument that temperature is the most important. What does she say?

Select the correct options in the last sentence:

Sara says:

"Temperature is the most important factor that determines the plant species that can grow at a particular elevation on a mountain. At the top of Frog Mountain it is cold (30 degrees Fahrenheit) and wet (2 ft of rain per year). At the bottom of Mt. Kimball, it is also cold (30 degrees Fahrenheit), but it does not get very much rain (6 inches per year). On Frog Mountain, there is a forest ecosystem at the top of the mountain and on Mt. Kimball, there is a forest ecosystem at the bottom of the mountain. At the top of Mt. Kimball the temperature is very, very cold and no plants can live there.

Because the plants growing on top of each mountain are #the same | different#, and the temperatures on the tops of each mountains are #the same | different#, we can conclude that temperature is #important | not important# for determining which types of plants can live at each elevation."

Target level: Argumentation level 2b

10. Which additional piece of reasoning supports Sara?

a. If the temperature increases, then forests should grow.

b. If the temperature at the top of Frog Mountain and the bottom of Mt. Kimball is the same, and the types of plants that grow there are the same, then the temperature is important.

c. If rainfall is important, then we should see an increase in the amount of plants.

d. If the temperature at the top of Mt. Kimball is higher than at the top of Frog Mountain, then the amount of plants should increase, too.

Target level: Argumentation level 2d

11. Anna argues back: 

"Rainfall is the most important factor that determines the plant species that can grow at a particular elevation on a mountain. As the elevation of Frog Mountain increases, the amount of rainfall increases. At the top of Frog Mountain it is cold (30 degrees Fahrenheit) and wet (2 ft of rain per year). As the elevation of Mt. Kimball increases, the amount of rainfall increases also. Tall trees grow at the top of Frog Mountain. No trees grow on the top of Mt. Kimball. Because the trees on top of each mountain are different, but the amount of rainfall at each elevation is the same, we can conclude that the amount of rainfall must be important for determining which types of plants can live at each elevation."

What is wrong with Anna's argument?

a. If the elevation is increasing, and the tree species are different, then temperature must be the most important.

b. If the amount of rainfall is the same, but the tree species are different, then something else must be affecting which trees can grow.

c. If Frog Mountain and Mt. Kimball both have forests, then it must be possible for temperature to affect plant species.

d. If rainfall is the most important, then it is not necessary to show the temperature.