Science · 6th Grade

Active learning ideas

Food Chains and Food Webs

Active learning works for this topic because students need to see the complexity of energy flow and relationships in ecosystems firsthand. Building and testing models lets them experience how disruptions ripple through systems, turning abstract concepts into concrete understanding.

• Common Core State Standards
• MS-LS2-2

• 20–35 min
• Pairs → Whole Class
• 3 activities

Activity 01

• Inquiry Circle
• 35 min · Small Groups

Collaborative Model: Build a Local Food Web

Provide groups with species cards for a local ecosystem (e.g., a freshwater pond or tallgrass prairie). Students draw arrows connecting organisms based on feeding relationships, then compare their webs to other groups' versions. The class discusses where their webs agree and disagree, and why the same ecosystem can produce different valid models.

Construct a food web for a local ecosystem.

Facilitation Tip

During the Collaborative Model activity, assign each group a specific organism and its energy source to ensure all roles are represented in the final web.

What to look for

Provide students with a list of 5-7 organisms from a local park or forest. Ask them to draw a simple food web connecting these organisms and label at least two trophic levels. Then, ask them to write one sentence predicting what might happen if the population of the top predator in their web decreased.

• Analyze
• Evaluate
• Create
• Self-Management
• Self-Awareness

Activity 02

• Simulation Game
• 30 min · Small Groups

Simulation Game: Predator Removal Experiment

Using a physical web model with yarn or string connecting organism cards, remove a top predator species and have students physically trace which connections are now disrupted. Groups predict the population effects at each level, then compare their predictions to a documented real-world trophic cascade like the wolf reintroduction at Yellowstone.

Predict what happens to an ecosystem when a top predator is removed.

Facilitation Tip

For the Predator Removal Experiment simulation, have students record population data in a shared table so the class can analyze trends together.

What to look for

Display an image of a simple food chain (e.g., grass -> rabbit -> fox). Ask students to write down the producer, primary consumer, and secondary consumer. Then, pose a question: 'What would happen to the fox population if a disease wiped out most of the rabbits?' Have students write a brief explanation.

• Apply
• Analyze
• Evaluate
• Create
• Social Awareness
• Decision-Making

Activity 03

• Think-Pair-Share
• 20 min · Pairs

Think-Pair-Share: Producer Collapse Scenario

Present a scenario: a drought reduces the grassland producer population by 70%. Pairs work through the food web to predict population changes at each trophic level, writing their reasoning before sharing with the class. The discussion highlights that effects are not always predictable and can travel in both directions through the web.

Analyze the impact of a decline in producer populations on an entire food web.

Facilitation Tip

In the Think-Pair-Share Producer Collapse activity, set a timer for 2 minutes of individual thinking to prevent students from jumping straight to the first idea they share with a partner.

What to look for

Present a scenario: 'Imagine a pond ecosystem where the algae population suddenly crashes due to pollution. What are three different organisms that would likely be affected, and how?' Facilitate a class discussion where students share their predictions and justify them based on food web principles.

• Understand
• Apply
• Analyze
• Self-Awareness
• Relationship Skills

A few notes on teaching this unit

Teach this topic by starting with familiar examples students can relate to, like backyard food webs, before moving to more complex systems. Use analogies they understand, such as money flow in a family budget, to explain energy transfer. Avoid overwhelming them with too many organisms at once; focus on depth over breadth to build strong foundational understanding.

Successful learning looks like students accurately representing energy transfer as one-way and limited, explaining how disruptions in one part of a food web affect others, and using evidence from models to support their reasoning. They should move from simple chains to recognizing the interconnectedness of food webs.

---

Watch Out for These Misconceptions

• During the Collaborative Model activity, watch for students who assume energy is recycled in the food web and reused exactly as it was in the previous organism.

  Use the passing chips model as a warm-up before the activity: have students pass 100 chips between groups, removing 90% each time to show energy loss and one-way flow, then connect this to the food web they build.

• During the Collaborative Model activity, watch for students who treat the food chain as a straight line with no branching or multiple connections.

  After building the initial web, have students count the number of incoming and outgoing arrows for each organism and highlight the organism with the most connections to emphasize the complexity of real food webs.

• During the Predator Removal Experiment simulation, watch for students who assume removing a predator will always benefit the prey population and the ecosystem overall.

  Have students revisit the Yellowstone wolf case study after the simulation, asking them to compare their initial predictions with the real outcomes and explain why their assumptions were incomplete.

---

Methods used in this brief

• Inquiry Circle
• Simulation Game
• Think-Pair-Share