Prairie Ecosystem Gizmo Answer Key

Name: Lauren Mendoza Date: 09-07-2022 Student Exploration: Prairie Ecosystem Directions: Follow the instructions to go through the simulation. Respond to the questions and prompts in the orange boxes. Vocabulary: carnivore, consumer, ecosystem, equilibrium, extinct, food chain, herbivore, organism, population, prairie, producer Prior Knowledge Questions (Do these BEFORE using the Gizmo.) An ecosystem consists of all organisms (living things) in an area, plus the natural landscape. A prairie is flat or gently rolling grassland with few trees, such as in parts of central United States and Canada. Organisms often found in a prairie ecosystem include prairie dogs, swift foxes, black-footed ferrets, and of course the grass itself. 1. Which organism (grass, prairie dog, ferret, or fox) do you think is a producer (does not depend on other organisms for its food)? prairie dog 2. Organisms that depend on other organisms for food are consumers. Which consumer you think is a herbivore (eats plants only)? prairie dog 3. Which consumers are carnivores (eat meat)? ferret and fox Gizmo Warm-up: Life on the Prairie 1. The population of prairie dogs is all the prairie dogs living in the village. In the Gizmo, what are the starting numbers of Grass: 4,000 Prairie dogs: 25,000 Ferrets: 80 Foxes: 10 2. Click Advance year 10 times. On the DATA tab, look at the Bar graph and the Line graph. Do the populations change very much, or are they in equilibrium (stable)? Explain. Yes because some animals have died and some plants have been ate Get the Gizmo ready: Activity A: ● Click Reset. ● Be sure Show populations is selected. Grass Question: How is grass important to a prairie ecosystem? 1. Observe: Remove ALL animals from the prairie by clicking the minus (–) button next to each animal many times. Click Advance year 20 times. Does grass survive by itself? Explain. Yes but some of it dies and more regrow Because grass does not depend on other organisms for food, it is a producer. Grass gets what it needs from the Sun, air, and soil. 2. Predict: Click Reset. Predict what will happen to the prairie dogs, ferrets and foxes if half of the grass were removed. Write “increase” or “decrease” in each blank below. Prairie dogs: 14,643 Ferrets: 67 Foxes: 10 3. Experiment: Remove about half of the grass by clicking the minus – button. There should now be about 2,000 tons of grass. Click Advance year twice, and look at the Bar graph or the Line graph. What happened to each population—increase or decrease? Prairie dogs: 14,643 Ferrets: 67 Foxes: 10 4. Think about it: What do you think will happen if you continue advancing years? They would begin to lose numerous animals. 5. Experiment: Test your prediction by clicking Advance year until 20 years have passed. A. What do you notice? The animals re-climbed since there was more grass. B. Does the ecosystem return to equilibrium? Yes C. How do you know? Plants grow again and additional creatures are produced. 6. Extend your thinking: Suppose a fire swept through the prairie. The animals ran away, but about half the grass was burned. What would be the long-term results of this natural event? It would regrow Activity B: Get the Gizmo ready: Making a food chain ● Click Reset. Question: How do animals affect the prairie ecosystem? 1. Form hypotheses: What do you think each animal in the food chain eats? (Experiment with the Gizmo to help you make your hypotheses.) Prairie dogs eat grass . Ferrets eat prairie dog . Foxes eat ferrets . 2. Predict: Based on your hypotheses, predict how the changes below will affect the other animals. Write either “increase” or “decrease” next to each “P” (for “prediction”) in the table. Change Add prairie dogs Add ferrets Add foxes Grass P: die Prairie dogs Ferrets P: gain more Foxes P: have more _______________________________________________________ _______________________________________________________ _______________________________________________________ A: it died A: they added 2 A: they had one P: gone P: half gone P: have more _______________________________________________________ _______________________________________________________ _______________________________________________________ A: have more A: lost 10,000 A: gained 2 P: die P: gained more P: die _______________________________________________________ _______________________________________________________ _______________________________________________________ A: died A: gained more A: lost 11 3. Test: Click Reset. Add as many prairie dogs as the Gizmo allows. Click Advance year once. Record the effects on the other three organisms in the table next to “A” (for “actual”). Then click Reset and do the same with ferrets, and then again with foxes. 4. Analyze: In a food chain, each animal eats only one other animal or plant. Based on your experiments, what is the food that each animal eats? Explain how you know. Prairie dogs eat plants . Ferrets eat the prairie dogs . Foxes eat ferrets . Explain: because if you add a lot of foxes the ferrets go missing and if you add grass it goes missing and if you add ferrets prairie dogs go missing 5. Apply: Now complete the Prairie Ecosystem food chain. Arrows point toward the animal that is eating. For example, “Mouse → Hawk” would mean that the mouse is eaten by the hawk. grass Activity C: Long term changes → prairie dog → ferret → fox Get the Gizmo ready: ● Click Reset. Introduction: Once common, the black-footed ferret is an endangered animal. In 1986 there were only 18 black-footed ferrets alive; today there are almost 1,000. Question: What would happen to the ecosystem, long-term, with no black-footed ferrets? 1. Form a hypothesis: Based on what you have seen so far, what do you think would happen if black-footed ferrets died out, or went extinct? Explain in detail. They would disappear because they would no longer have the prerequisites to establish the food chair, and they would just perish. 2. Experiment: Click Reset, and remove all the ferrets from the prairie dog town. Click Advance year for 12 years. What happens? They all perished 3. Analyze: Why did removing ferrets have such a powerful effect on the prairie ecosystem? I created the food chain, and everything perished. 4. On your own: Investigate other major changes to the prairie ecosystem. Run each experiment for 20 years to see what the long-term results would be. A. Give an example of a change that the ecosystem was able to recover from and return to equilibrium. i did no prairie dogs or ferrets and everything died B. Give an example of a change that the ecosystem was not able to recover from. Can you explain why? It will pass away from and remain that way for a very long period.