The Living World: Senior Cycle Biology · 5th Year

Active learning ideas

Food Chains, Food Webs, and Trophic Levels

Active learning helps students grasp energy flow and interdependence in ecosystems by making abstract concepts concrete. When students manipulate cards, draw webs, or simulate disruptions, they move beyond memorizing terms to understanding relationships and consequences in real habitats like Irish coastal dunes or grasslands.

• NCCA Curriculum Specifications
• NCCA: Senior Cycle - Ecology
• NCCA: Senior Cycle - The Study of Life

• 30–50 min
• Pairs → Whole Class
• 4 activities

Activity 01

• Jigsaw
• 30 min · Pairs

Card Sort: Building Food Chains

Provide cards with Irish species names, images, and trophic roles. In pairs, students sequence them into three food chains, labeling energy flow arrows with percentages. Pairs then share one chain with the class for peer feedback.

Explain why energy decreases at successive trophic levels in an ecosystem.

Facilitation Tip

During Card Sort: Building Food Chains, circulate to listen for students explaining their chains aloud; this oral rehearsal strengthens understanding better than silent sorting.

What to look for

Provide students with a list of 10-15 organisms found in a specific Irish habitat (e.g., a coastal salt marsh). Ask them to draw a food web connecting these organisms and label at least three trophic levels. Then, ask them to write one sentence explaining why energy transfer between levels is inefficient.

• Understand
• Analyze
• Evaluate
• Relationship Skills
• Self-Management

Activity 02

• Simulation Game
• 45 min · Small Groups

Simulation Game: Food Web Disruption

Distribute species role cards to small groups representing a Irish bog ecosystem. Students pass 'energy tokens' along web paths. Remove a producer card and discuss resulting trophic collapses, recording changes in a shared diagram.

Analyze the impact of removing a producer from a food web.

Facilitation Tip

For Simulation: Food Web Disruption, assign roles like ‘population tracker’ or ‘energy bar’ keeper to keep all students involved in the process.

What to look for

Display a simplified food web on the board. Ask students to write down: 1. One producer, 2. One primary consumer, 3. One secondary consumer, and 4. What would happen to the population of the primary consumer if the producer was removed? Collect responses to gauge understanding of roles and dependencies.

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

Activity 03

• Jigsaw
• 50 min · Small Groups

Field Sketch: Local Web Mapping

Students observe a schoolyard or nearby habitat, sketch producers and consumers, and construct a food web on paper. Groups compile sketches into a class mural, annotating trophic levels and energy flow.

Construct a food web for a local Irish ecosystem, identifying producers, consumers, and decomposers.

Facilitation Tip

In Field Sketch: Local Web Mapping, provide clipboards and colored pencils to encourage careful observation and accurate labeling of connections.

What to look for

Pose the question: 'Imagine a disease drastically reduces the population of a specific herbivore in Ireland's grassland ecosystems. What are two potential consequences for the producers and two potential consequences for the carnivores?' Facilitate a class discussion, guiding students to articulate cascading effects and interdependence.

• Understand
• Analyze
• Evaluate
• Relationship Skills
• Self-Management

Activity 04

• Formal Debate
• 40 min · Whole Class

Formal Debate: Trophic Impact Analysis

Whole class divides into teams. Present scenarios like otter decline in Irish rivers. Teams construct mini-webs, predict effects, and debate outcomes, voting on most accurate predictions.

Explain why energy decreases at successive trophic levels in an ecosystem.

What to look for

Provide students with a list of 10-15 organisms found in a specific Irish habitat (e.g., a coastal salt marsh). Ask them to draw a food web connecting these organisms and label at least three trophic levels. Then, ask them to write one sentence explaining why energy transfer between levels is inefficient.

• Analyze
• Evaluate
• Create
• Self-Management
• Decision-Making

A few notes on teaching this unit

Start with a simple coastal dune example to anchor ideas, then gradually increase complexity by adding species and links. Avoid rushing to abstract trophic pyramids before students can trace energy through real organisms. Research shows that students learn best when they first experience concrete models before moving to symbolic representations like energy pyramids or transfer efficiency calculations.

By the end of these activities, students should confidently construct food chains and webs for local ecosystems, label trophic levels accurately, and explain energy loss using the 10 percent rule. They should also analyze how changes to one species ripple through the system, demonstrating cause-and-effect reasoning.

---

Watch Out for These Misconceptions

• During Card Sort: Building Food Chains, watch for students arranging longer chains at higher trophic levels, believing energy grows.

  Direct students to physically pass energy tokens (e.g., counters) along the chain, demonstrating that only about 10 percent transfers; have peers explain why the pile shrinks at each step.

• During Card Sort: Building Food Chains, watch for students creating isolated chains without overlapping links.

  Prompt students to rearrange their cards to include multiple feeding links, asking them to identify shared prey or predators; circulate to highlight overlaps during discussion.

• During Simulation: Food Web Disruption, watch for students omitting decomposers entirely or treating them as optional.

  Require each group to include decomposer cards in their initial web, then run a ‘no decomposer’ scenario to observe nutrient recycling failure; debrief the essential role of decomposers in sustaining producers.

---

Methods used in this brief

• Jigsaw
• Simulation Game
• Formal Debate