Lesson 3 of 8
Objective: Students will be able to analyze data from a simple food chain and explain complex relationships in food webs
To start this lesson, I play Mr. Parr's "Energy Flow" song.
As the song is playing I have students write down the vocabulary words they recognize. I am looking for photosynthesis, producers, decomposers, food chains, food webs, omnivores, etc. I then invite students to share one of the words they wrote down, along with it's definition. The goal of this exercise is to provide students with an opportunity to review the vocabulary.
Note to teachers: I do not ask students to turn this in since it is meant as a simple vocabulary review. However, some students decided to do so, and I am including their work for you to get an idea of what they recorded. (Hook SW)
Note to teachers: Unfortunately, the "Figs and Monkeys" simulator I used for this lesson is no longer available. I am now using this alternate one: Sunny Meadows with this new Food Chains and Food Webs sheet.
I tell students that today they will first work on a simulation to deepen their understanding of the relationship between producers and consumers. I distribute the Food Chains and Food Webs sheet, and display the Food Chain Simulator. I go over the instructions for this simulator with the students, pointing out what data needs to be collected (numbers at the start, end and number of cycles) (SP2 - Develop and/or use a model to generate data to test ideas about phenomena in natural or designed systems). Watch as students make sense of the data the simulation provides and discover the importance of predators and prey to maintain equilibrium in an ecosystem.
Note to teachers: Today each student will be working on his/her own device. However, I tell them that it is OK to talk to each other about what they see and write down their answers, since this is what scientists do.
Although students can move on to the next activity as soon as they finish, once I notice everyone has completed the Figs and Monkeys activity I reconvene the class and hold a brief whole class discussion on their findings and the answers they wrote down in this section.
* The figs and monkeys simulator requires the shockwave plug-in. It only plays on Firefox. It will not play on Chrome or IE.
During this activity, students are asked to choose a habitat and follow the clues to figure out how different organisms depend on one another. This activity is reinforcing the concepts learned about how energy cycles through in an ecosystem, and opens the door to the cycling of matter which will be explicitly taught in subsequent lessons (CCC Energy and Matter The transfer of energy can be tracked as energy flows through a designed or natural system). As students connect the dots between organisms they are using and developing models of a food web (SP2). The work documents they create while visiting the interactives provide opportunities to derive meaning from scientific text (SP8), as well as make inferences and draw conclusions from the information they are interacting with. Listen in as a student uses the information provided and connects it to the vocabulary previously taught, and stay tuned in for an explanation of how the interactive makes learning about interdependence "easier".
Note to teachers: Much on the information gathered in the document is textual information. I have students do this as a way to ensure that students interact with all the snippets of text, which identify the relationship between the different components of the ecosystems presented. When I review the work (SW1, SW2, SW3), I pay attention to the following questions:
- Explain how the data you gathered here relates to the work we did yesterday on energy flow. The answer reveals whether students are able to make the connection between the number of organisms at each level and the amount of energy available.
- If the leopards became extinct, how might this affect the other species that are connected to it. The answer tells me whether the students are able to identify how the presence of top predators is invaluable to maintain a balance in the population of other organisms.
- Imagine that the speckle-lipped mabuya became overpopulated in the bai. How might this affect the ecosystem and Do you think the golden barb could survive if spiders in the river area became extinct? Their answers reveal whether students understand how each organisms plays an important role, so their presence or absence has far reaching effects, beyond their immediate predator or prey.
To close this lesson, I ask students to respond to the following question, posted on Edmodo:
"What do you think would happen if ALL of the decomposers became extinct?"
As you can see, their answers recognize that decomposers are responsible for recycling nutrients back into the ecosystem, and that without them, organisms would not rot. In the discussion we had while students were answering, we did agree that weathering and erosion would still work to take care of the corpses, but the process is different from what would be required to provide nutrients for organisms.