Biology · Grade 11

Active learning ideas

Fungi: Decomposers and Symbionts

Students learn best by doing, especially when studying fungi, which are often invisible or misunderstood. Active observation and modeling help learners see how fungi function in ecosystems through direct engagement with living systems and materials.

• Ontario Curriculum Expectations
• HS-LS2-3
• HS-LS2-6

• 35–50 min
• Pairs → Whole Class
• 4 activities

Activity 01

• Stations Rotation
• 45 min · Small Groups

Lab Demo: Bread Mold Decomposition

Provide students with sterile bread slices at different moisture levels in petri dishes. Have them observe and sketch daily mold growth over a week, measure colony diameters, and compare decomposition rates across conditions. Conclude with a class discussion on nutrient recycling.

Compare the nutritional strategies of fungi with those of plants and animals.

Facilitation Tip

During the Bread Mold Decomposition lab, have students predict and record visible changes daily to connect fungal growth with nutrient absorption.

What to look for

Present students with three scenarios: one describing a plant absorbing nutrients from soil via mycorrhizae, one describing a dead log being broken down, and one describing yeast fermenting sugar. Ask students to identify which scenario best illustrates fungi acting as symbionts, decomposers, or in a beneficial economic role, and to justify their choice with one key characteristic.

• Remember
• Understand
• Apply
• Analyze
• Self-Management
• Relationship Skills

Activity 02

• Stations Rotation
• 50 min · Pairs

Pairs Model: Mycorrhizal Symbiosis

Pairs plant bean seeds in pots: one with mycorrhizal fungi inoculum, one without. Water consistently and measure growth weekly for three weeks, recording root development and biomass. Discuss how fungi enhance phosphorus uptake.

Explain the ecological importance of fungi as decomposers and symbionts.

Facilitation Tip

For the Mycorrhizal Symbiosis model, assign roles clearly so each pair can document both plant and fungal benefits shown in their diagram.

What to look for

Pose the question: 'If all fungi disappeared tomorrow, what would be the most significant ecological consequence, and why?' Facilitate a class discussion where students must support their claims by referencing the roles of fungi as decomposers and symbionts.

• Remember
• Understand
• Apply
• Analyze
• Self-Management
• Relationship Skills

Activity 03

• Stations Rotation
• 40 min · Small Groups

Stations Rotation: Fungi Nutrition Strategies

Set up stations for plant photosynthesis demo, animal digestion model, fungal enzyme action on gelatin, and spore print making. Groups rotate every 10 minutes, noting differences in nutrient acquisition and recording in journals.

Assess the impact of fungal diseases on agriculture and human health.

Facilitation Tip

At the Station Rotation stations, circulate with guiding questions like, 'What does this structure tell you about how fungi eat?' to prompt reasoning.

What to look for

On an index card, have students draw a simple diagram of a fungal hypha interacting with a plant root. Ask them to label the hypha, the root, and one nutrient or sugar exchanged between them, and write one sentence explaining the benefit to the plant.

• Remember
• Understand
• Apply
• Analyze
• Self-Management
• Relationship Skills

Activity 04

• Stations Rotation
• 35 min · Whole Class

Whole Class: Fungal Disease Impact Analysis

Present case studies on potato blight and athlete's foot. Students vote on management strategies in polls, then debate economic and health effects using provided data sheets. Summarize key prevention methods.

Compare the nutritional strategies of fungi with those of plants and animals.

Facilitation Tip

When analyzing fungal disease impact, provide short case studies so students can trace ecological ripple effects from data tables.

What to look for

Present students with three scenarios: one describing a plant absorbing nutrients from soil via mycorrhizae, one describing a dead log being broken down, and one describing yeast fermenting sugar. Ask students to identify which scenario best illustrates fungi acting as symbionts, decomposers, or in a beneficial economic role, and to justify their choice with one key characteristic.

• Remember
• Understand
• Apply
• Analyze
• Self-Management
• Relationship Skills

A few notes on teaching this unit

Teachers find success when they start with the tangible—visible fungi like bread mold or mushrooms—before abstract concepts. Avoid over-reliance on diagrams early; let students observe hyphae under microscopes firsthand. Research shows that when students manipulate living cultures or create 3D models, their understanding of fungal roles deepens more than through lecture alone.

By the end of these activities, students will confidently identify fungal structures, distinguish between decomposition and symbiosis, and explain two ways fungi support ecosystems. They will use evidence from hands-on tasks to revise initial misconceptions and support claims with observable data.

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Watch Out for These Misconceptions

• During the Bread Mold Decomposition lab, watch for students labeling fungi as plants because they grow from soil. Redirect by asking them to examine the fuzzy texture under a hand lens and compare it to plant roots, noting the absence of green color and the presence of thread-like hyphae.

  During the Bread Mold Decomposition lab, after students observe the mycelium growing on bread, have them sketch the hyphae network and contrast it with a plant root diagram provided at the station. Ask them to identify one feature that proves fungi are not plants.

• During the Mycorrhizal Symbiosis model, watch for students assuming all fungi harm living tissue. Redirect by having them examine the plant-fungi pot trials and note the increased root growth in mycorrhizal pots compared to control pots.

  During the Mycorrhizal Symbiosis model, when students observe the plant pots, ask them to measure root length and compare the mycorrhizal plants to control plants. Have them explain how increased nutrient absorption contradicts the idea that fungi only harm living tissue.

• During the Station Rotation: Fungi Nutrition Strategies, watch for students thinking fungi reproduce only asexually. Redirect by having them analyze the life cycle diagrams at the station and compare the sexual and asexual phases shown in the spore print activity.

  During the Station Rotation: Fungi Nutrition Strategies, after students complete the spore print activity, ask them to map the stages of fungal reproduction on a poster, labeling plasmogamy and karyogamy using the diagrams provided. Have them justify why both sexual and asexual phases are present.

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Methods used in this brief

• Stations Rotation