Student Exploration: Plants and Snails

Name: Date: Student Exploration: Plants and Snails Directions: Follow the instructions to go through the simulation. Respond to the questions and prompts in the orange boxes. Vocabulary: aerobic respiration, bromothymol blue (BTB), carbon dioxide-oxygen cycle, indicator, interdependence, photosynthesis Prior Knowledge Questions (Do these BEFORE using the Gizmo.) 1.​ What important gas do we take in when we breathe? oxygen 2.​ Why don’t we run out of the important gases that we need to stay alive? because it is a cycle that never stops 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. 1.​ With the lights set to on, drag a snail into one test tube and a plant into another. Press Play ( each tube? ). After 24 hours, what is the color of The plant tube is blue and the snail tube is yellow. 2.​ 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. A.​ When the water turns blue, which gas is most common? O2 B.​ When the water turns yellow, which gas is most common? CO2 C.​ What does it tell you when the water is green? That the CO2 and the O2 are even. Reproduction for educational use only. Public sharing or posting prohibited. © 2020 ExploreLearning™ All rights reserved Get the Gizmo ready: Activity A: Gases in and gases out ●​ 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? 1.​ Collect data: Use the Gizmo to learn what gases plants and animals take in and give off. Try it in both light and dark. Record your results below. If you do more than five experiments, write your extra results in your notebook or on separate sheets of paper. What is in the tube Lights: on/off Results Snail Off O2 is 1.8 CO2 is 10.2 and the water is yellow Plant Off O2 is 4.4 CO2 is 7.6 and the water is green Snail Plant 2.​ Analyze: Study your data on gases given off by plants. A.​ What gas do plants give off in the light? B.​ How about in the dark? 3.​ Analyze: Study your data on gases given off by animals. A.​ What gas do animals give off in the light? B.​ How about in the dark? C.​ How do these results compare to your plant results? 4.​ Infer: Describe the carbon dioxide-oxygen cycle by completing the sentences below: Animals breathe in In sunlight, plants take in and breathe out and release Reproduction for educational use only. Public sharing or posting prohibited. © 2020 ExploreLearning™ All rights reserved Get the Gizmo ready: ●​ ●​ ●​ ●​ Activity B: Interdependence 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? 1.​ Observe: Put one sprig of Elodea and one snail in a test tube with the lights on. Click Play. A.​ Does the color of the water in the tube change? B.​ What happens to the O2 and CO2 levels? 2.​ Predict: Without using the Gizmo, predict what you think will happen to the gas levels in each case listed below. (Leave the Actual result column blank for now.) Tube Prediction Actual result 2 snails, 2 sprigs, lights on 1 snail, 2 sprigs, lights on 1 snail, 2 sprigs, lights off 3.​ Run Gizmo: Now run the Gizmo to test your predictions. Record your findings in the table. 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? 1.​ 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. A. How do the oxygen (O2) and carbon dioxide (CO2) levels change over time? B. What is always true about the total amount of O2 and CO2 in the test tube? Reproduction for educational use only. Public sharing or posting prohibited. © 2020 ExploreLearning™ All rights reserved C. What happens when the CO2 reaches zero? 2.​ Revise and repeat: Click Reset. Remove the plants. Repeat the experiment with two snails. A. How do the gas levels change? B. What is the total of O2 and CO2? O2 CO2 Reproduction for educational use only. Public sharing or posting prohibited. © 2020 ExploreLearning™ All rights reserved