<p>Name______Date______Per______</p><p>Biology – Dr. Della Donna HS-LS2-4 I can use mathematical representations to support claims for the cycling of matter and flow of energy among organisms in an ecosystem </p><p>Trophic Levels lab</p><p>Vocabulary: - consumer - producer - carnivore -herbivore - omnivore - food chain -food web - trophic level</p><p>Density-independent factor: factors such as storms, fires, extremes, temp, etc. that affect populations regardless of their density.</p><p>Density-dependent factors: environmental factors such as diseases and competition that depend on the number of members in a population per unit area.</p><p>Roles: Grass: 18 students; popcorn bags Rabbits: 12 students Snakes: 3 students Hawk: 1 student Data collectors: 2 students</p><p>INSTRUCTIONS – read carefully</p><p>Each PRODUCER gets a small bag of popcorns: producers stand spread out in the room, evenly distributed. If approached by a rabbit and the rabbit gently taps its shoulder, the producer gives the bag of popcorn to the rabbit. </p><p>Goal of RABBITS: to get as many bags as possible. Rabbits will be released first to get as many bags of popcorns as possible from the producers and then get back to their seat without being consumed by a predator. If a rabbit loses its bag, it’s dead. If it can get to its seat with at least one bag, it is alive.</p><p>Goal of SNAKES is to get as many bags as possible before time is called. Snakes will be released after 10 seconds delay to get as many bags as possible from rabbits. Snakes can also get to their seat (so they can’t be consumed by a predator) but focus should be on getting bags from rabbits and grass.</p><p>HAWK is released last to get as many bags as possible from rabbits and snakes.</p><p>My role was: ______Table 1: Organism Starting # of organisms Ending # of organisms Grass Rabbits Snakes Hawks This activity will be repeated with different scenarios:  Fire  Disease These two scenarios will start with less of numbers of organisms in each group. Predict what will happen with each scenario. ______Table 2 – Fire scenario: Organism Starting # of organisms Ending # of organisms Grass Rabbits Snakes Hawks</p><p>Table 3 – Disease scenario: Organism Starting # of organisms Ending # of organisms Grass Rabbits Snakes Hawks</p><p>Complete the lab: 1. Complete all tables 2. Create an energy pyramid. Label each trophic level and indicate the direction of the energy flow 3. Create a graph for each scenario. Plot all organisms on the same graph, using different color pencils to indicate population’s change. 4. Answer the questions</p><p>Grading rubric: Energy pyramid: 30 points  Labeling is complete and correct  Energy source is indicated  Flow of energy is indicated  Loss of energy per level is quantified Graph: 30 points  Each population’s change is indicated and plotted with different colors  Graph is correctly labeled  Title is present Questions and answers: 40 points  All questions are addressed in complete sentences</p><p>Questions: a. Why wouldn't each of the species eventually die out in the first scenario in nature? b. How do top predators or keystone species keep the trophic pyramid balanced? c. Explain what would eventually happen if disease hits the rabbits instead of the snakes and hawks in real life d. Which scenario represented a density-independent factor? How? What would have happened without completion?</p>