Microorganisms: Bacteria and Fungi

Active learning connects students to the invisible world of microorganisms by making it tangible. Hands-on work with live cultures and models helps students see how bacteria and fungi operate in real time, turning abstract concepts into memorable experiences. When students observe growth, culture results, or simulation outcomes, they build lasting understanding of roles and impacts that textbooks alone cannot provide.

• Primary 4
• Science
• 4 activities
• 30 min–45 min

Learning Objectives

1. Compare the cellular structures and reproductive methods of bacteria and fungi.
2. Explain the beneficial roles of specific bacteria (e.g., in yogurt production) and fungi (e.g., in decomposition).
3. Analyze the harmful effects of certain bacteria and fungi on food preservation and human health.
4. Predict the potential societal consequences of widespread antibiotic resistance on common infections.
5. Classify given examples of microorganisms as either bacteria or fungi based on their characteristics.

Inquiry Circle

⏱ 30 min·Small Groups

Observation Lab: Bread Mould Growth

Provide moist bread slices in sealed bags. Students predict growth over 3-5 days, sketch daily changes with hand lenses, measure mould spread, and note conditions like warmth. Conclude by classifying observations as fungal characteristics.

Prepare & details

Explain the beneficial and harmful roles of bacteria in ecosystems and human health.

Facilitation Tip: During the Observation Lab, remind students to label plates with dates and initials to track mold growth patterns over time.

Setup: Groups at tables with access to source materials

Materials: Source material collection, Inquiry cycle worksheet, Question generation protocol, Findings presentation template

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

Inquiry Circle

⏱ 40 min·Pairs

Culture Station: Yogurt Bacteria

Pairs heat milk to 85°C, cool to 45°C, stir in yogurt starter, and incubate overnight. Next lesson, taste samples, discuss bacterial fermentation turning milk sour, and link to digestion benefits.

Prepare & details

Compare the characteristics of bacteria and fungi.

Facilitation Tip: At the Culture Station, have students prepare two slides: one stained and one unstained, so they can compare bacterial shapes under the microscope.

Setup: Groups at tables with access to source materials

Materials: Source material collection, Inquiry cycle worksheet, Question generation protocol, Findings presentation template

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

Jigsaw

⏱ 45 min·Small Groups

Jigsaw: Bacteria vs Fungi

Assign small groups one organism. They list traits, roles, and images on posters, then rotate to teach peers and complete comparison charts. Whole class shares key differences.

Prepare & details

Predict the impact of widespread antibiotic resistance on human societies.

Facilitation Tip: For the Jigsaw Puzzle, assign each small group one category to research and present, ensuring all students contribute to the final comparison chart.

Setup: Flexible seating for regrouping

Materials: Expert group reading packets, Note-taking template, Summary graphic organizer

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

Simulation Game

⏱ 35 min·Small Groups

Simulation Game: Antibiotic Resistance

Use beads as bacteria on trays. Students apply 'antibiotics' (remove colours) over rounds, showing survivors multiply. Discuss overuse impacts on health.

Prepare & details

Explain the beneficial and harmful roles of bacteria in ecosystems and human health.

Facilitation Tip: In the Simulation Game, pause after each round to ask students to predict what will happen next and explain their reasoning aloud.

Setup: Flexible space for group stations

Materials: Role cards with goals/resources, Game currency or tokens, Round tracker

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

Teaching This Topic

Teachers should pair direct instruction with inquiry, using demonstrations and guided questions to scaffold observations. Avoid overwhelming students with too many new terms at once; instead, focus on one concept per activity and connect it to prior knowledge. Research shows that students grasp structural differences better when they see cells under the microscope before discussing functions, so sequence activities to build from concrete to abstract.

What to Expect

By the end of these activities, students will confidently distinguish bacteria from fungi, explain at least two beneficial roles and two harmful roles, and describe how microorganisms influence ecosystems and health. They will use evidence from their observations to challenge assumptions and communicate findings clearly in discussions and written work.

Watch Out for These Misconceptions

Common Misconception

During Culture Station: Yogurt Bacteria, watch for statements like 'This yogurt has bad bacteria because it smells sour.' Redirect by asking students to compare the yogurt culture to harmful bacteria examples and discuss why sourness signals fermentation, not spoilage.

What to Teach Instead

During Culture Station: Yogurt Bacteria, students should taste and observe the yogurt, noting its texture and smell. Use this to contrast beneficial fermentation with harmful spoilage, asking students to identify key differences in smell and appearance.

Common Misconception

During Observation Lab: Bread Mould Growth, watch for students calling mould a plant because it cannot move. Redirect by having them compare the mould’s thread-like structures to plant roots and ask how each absorbs nutrients.

What to Teach Instead

During Observation Lab: Bread Mould Growth, guide students to sketch the mould’s hyphae and discuss how these structures absorb nutrients from bread. Use the sketch to highlight that fungi absorb nutrients externally, unlike plants that photosynthesise.

Common Misconception

During Simulation Game: Antibiotic Resistance, watch for students saying 'microbes don’t really matter because we can’t see them.' Redirect by asking them to recall food spoilage or infections they have experienced and connect these to the simulation’s outcomes.

What to Teach Instead

During Simulation Game: Antibiotic Resistance, after each round, ask students to record how many 'healthy cells' remain and discuss how this relates to treating infections. Link the game’s results to real-world scenarios like strep throat treatment to make impacts visible.

Assessment Ideas

Quick Check

After the Jigsaw Puzzle: Bacteria vs Fungi, present students with a set of images and ask them to label each as 'Bacteria' or 'Fungi' and write one characteristic that supports their choice. Collect responses to identify lingering misconceptions.

Discussion Prompt

After the Simulation Game: Antibiotic Resistance, pose the question: 'Your simulation showed that some bacteria survived the antibiotic. What would happen if 90% of bacteria in your body were resistant? Discuss two specific ways this would change daily life in your community.' Circulate to listen for evidence-based reasoning.

Exit Ticket

After the Culture Station: Yogurt Bacteria, have students write on an index card one example of a beneficial role of bacteria or fungi and one example of a harmful role. Then, they should write one sentence explaining why antibiotic resistance is a concern, using evidence from the activity.

Extensions & Scaffolding

• Challenge students who finish early to design a public health poster warning about antibiotic resistance, using data from the simulation game.
• For students who struggle, provide labeled diagrams of bacterial and fungal cells to annotate during the Jigsaw Puzzle activity.
• Deeper exploration: Invite students to research a specific fungal pathogen or bacterial symbiosis and present a case study to the class using images or models.

Key Vocabulary

Microorganism	A microscopic organism, too small to be seen with the naked eye, such as bacteria or fungi.
Bacteria	Single-celled organisms lacking a nucleus; they reproduce by dividing and can be found in many environments, some beneficial and some harmful.
Fungi	Organisms like molds and yeasts that can be single-celled or multicellular; they absorb nutrients and reproduce using spores.
Antibiotic Resistance	The ability of bacteria to survive exposure to antibiotics, making infections harder to treat.
Decomposition	The process by which dead organic substances are broken down into simpler organic or inorganic matter, often carried out by bacteria and fungi.