Prior Knowledge Questions (Do these BEFORE using the Gizmo.)
Question 1
1.
Question 2
2.
Why don’t we run out of the important gases that we need to stay alive?
Gizmo Warm-up
In the Plants and Snails Gizmo, each of the test tubes contains water and a small amount of bromothymol blue (BTB). BTB is a chemical indicator. An indicator changes color when the chemicals in the water change.
Question 3
3.
Select Show oxygen and CO2 values. Place the O2/CO2 probe in each tube. The probe shows the levels of two gases, oxygen (O2) and carbon dioxide (CO2), in the tubes. We call these amounts the gas levels.
Question 4
4.
Question 5
5.
Question 6
6.
What does it tell you when the water is green?
Activity A: Gases in and gases out
Get the Gizmo ready:
Click Reset
Clear all of the test tubes.
Turn on Show oxygen and CO2 values.
Question: What gases do plants and animals take in and what do they give off?
Collect data: Use the Gizmo to learn what gases plants and animals take in and give off. Try it in both light and dark.
Question 7
7.
Question 8
8.
Question 9
9.
Question 10
10.
Question 11
11.
How do these results compare to your plant results? (especially plants in the dark)
Question 12
12.
Activity B: Interdependence
Get the Gizmo ready:
Click Reset.
Clear all of the test tubes.
Turn the light switch to on.
Check Show oxygen and CO2 values.
Question: How do plants and animals depend on each other?
Observe: Put one sprig of Elodea and one snail in a test tube with the lights on. Click Play.
Question 13
13.
Question 14
14.
Think about ...
What would happen if
you had two snails, and two sprigs with the lights on?
you had two snails and two springs with the lights off?
Run a few different scenarios and record your findings in your note book
Question 15
15.
Generalize: Describe how plants and animals each contribute to the survival of the other. Be specific.
Activity C: The carbon-oxygen balance
Get the Gizmo ready:
Click Reset.
Clear all of the test tubes.
Turn the light switch to on.
Check Show oxygen and CO2 values.
Question: How are the amounts of oxygen and carbon dioxide related to each other?
Observe: Put two Elodea sprigs into a test tube. Put the O2/CO2 probe into the tube with the Elodea. Click Play. As the Gizmo runs, Pause it a few times.
Question 16
16.
Question 17
17.
Question 18
18.
What happens when the CO2 reaches zero?
Revise and repeat: Click Reset and run the experiment again, this time with the lights off.
Question 19
19.
Question 20
20.
What is the total of O2 and CO2?
Revise and repeat: Click Reset. Remove the plants. Repeat the experiment with two snails. Leave the lights OFF and just remove the plants.
Question 21
21.
Question 22
22.
What is the total of O2 and CO2?
Question 23
23.
Challenge: In the process of photosynthesis, plants use carbon dioxide (CO2), water (H2O), and light energy to produce a sugar (C6H12O6) and oxygen (O2). In the process of aerobic respiration, animals and plants release energy from sugar and oxygen and produce carbon dioxide and water. The chemical equations that describe these reactions look like this: