The Discovery of Germs and Hygiene

Active learning helps Year 2 students grasp why germs and hygiene matter by making invisible concepts visible. Hands-on experiments and role-plays turn abstract discoveries into memorable, tangible experiences that build lasting understanding.

• Year 2
• History
• 4 activities
• 20 min–35 min

Learning Objectives

1. Explain how microscopic organisms called germs can cause illness, citing examples from historical accounts.
2. Compare the effectiveness of hygiene practices before and after the discoveries of Pasteur and Lister.
3. Classify common hygiene actions, such as handwashing and wound cleaning, based on their germ-killing properties.
4. Identify the key contributions of Louis Pasteur and Joseph Lister to the understanding of germs and hygiene.

Document Mystery

⏱ 35 min·Small Groups

Experiment Station: Pasteur's Flask Test

Prepare jars with clear liquid: some sealed, others with gauze covers or open. Students observe daily for mould growth over a week (use pre-made samples for speed). Groups record drawings and discuss how germs travel. Conclude with class share-out on findings.

Prepare & details

What are germs and how can they make people ill?

Facilitation Tip: During Pasteur's Flask Test, ask students to predict what will happen to the broth in each flask before the experiment starts to spark curiosity and reasoning.

Setup: Groups at tables with document sets

Materials: Document packet (5-8 sources), Analysis worksheet, Theory-building template

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

Document Mystery

⏱ 30 min·Small Groups

Role-Play: Lister's Operating Theatre

Divide class into surgeons, nurses, and patients. First round acts a 'dirty' surgery with pretend germs (glitter). Second round uses 'antiseptic' sprays and washing. Students vote on which feels safer and why.

Prepare & details

How did washing hands and keeping things clean help patients get better?

Facilitation Tip: In Lister's Operating Theatre, assign clear roles like surgeon, nurse, and patient to ensure every student participates actively in the role-play.

Setup: Groups at tables with document sets

Materials: Document packet (5-8 sources), Analysis worksheet, Theory-building template

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

Document Mystery

⏱ 20 min·Pairs

Glitter Germs: Hand Hygiene Challenge

Apply lotion and glitter to hands as 'germs'. Students wash with soap under UV light to reveal residue. Pairs compare before/after photos and explain steps for full removal.

Prepare & details

Why is it important to keep hospitals and doctor's rooms very clean?

Facilitation Tip: For Glitter Germs, use black light in a dark corner of the classroom to make glitter ‘germs’ glow, reinforcing the idea that germs spread even when invisible.

Setup: Groups at tables with document sets

Materials: Document packet (5-8 sources), Analysis worksheet, Theory-building template

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

Document Mystery

⏱ 25 min·Whole Class

Timeline Walk: Hygiene Heroes

Create a floor timeline with Pasteur and Lister milestones. Students add sticky notes with modern hygiene links, then walk and narrate as a chain.

Prepare & details

What are germs and how can they make people ill?

Facilitation Tip: During the Timeline Walk, have students physically move to different stations to place events in order, reinforcing sequencing and historical connections.

Setup: Groups at tables with document sets

Materials: Document packet (5-8 sources), Analysis worksheet, Theory-building template

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

Teaching This Topic

Teach this topic by linking hands-on activities to historical evidence, helping students see how science builds on discoveries. Avoid overwhelming students with too many facts; instead, focus on the big ideas: germs are invisible, they cause illness, and hygiene saves lives. Research shows that concrete experiences followed by guided reflection help young learners connect cause and effect in science.

What to Expect

Successful learning looks like students confidently explaining how germs spread, demonstrating proper handwashing, and describing the impact of sterilization on patient survival. They should connect Pasteur’s experiments to Lister’s practices with clear, evidence-based reasoning.

Watch Out for These Misconceptions

Common Misconception

During Glitter Germs, watch for students who think glitter germs are visible without special tools.

What to Teach Instead

During Glitter Germs, remind students that glitter is a model for germs, and in reality, germs need microscopes to see. Use the UV light demonstration to show how tools reveal what we cannot see.

Common Misconception

During Role-Play: Lister's Operating Theatre, watch for students who believe doctors always washed hands before Lister’s time.

What to Teach Instead

During Role-Play: Lister's Operating Theatre, have students compare their ‘before’ and ‘after’ role-plays directly, pointing out differences in cleanliness and outcomes to correct this idea.

Common Misconception

During Experiment Station: Pasteur's Flask Test, watch for students who think air itself causes decay.

What to Teach Instead

During Experiment Station: Pasteur's Flask Test, use the swan-neck flasks to show that air alone does not cause decay if germs are trapped. Ask students to explain why the straight-neck flask spoiled but the curved one stayed clear.

Assessment Ideas

Quick Check

After Glitter Germs, present students with pictures of different scenarios (e.g., a dirty wound, unwashed hands, a clean operating room, milk). Ask them to sort the pictures into two groups: 'Helps stop germs' and 'Helps germs spread'. Discuss their choices, focusing on hygiene practices.

Discussion Prompt

During Role-Play: Lister's Operating Theatre, pose the question: 'Imagine you are a patient in a hospital before Louis Pasteur and Joseph Lister made their discoveries. What might happen to you, and why was it so dangerous?' Encourage students to use vocabulary like 'germs' and 'infection' in their answers.

Exit Ticket

After Pasteur's Flask Test, give students a slip of paper and ask them to draw one thing they learned about keeping clean to stay healthy. They should also write one sentence explaining why that action is important, referencing either Pasteur or Lister.

Extensions & Scaffolding

• Challenge: Ask students to research another hygiene pioneer like Ignaz Semmelweis and present a short fact or drawing about his contribution.
• Scaffolding: Provide sentence starters for the hand hygiene reflection, such as "I learned that washing hands helps because..."
• Deeper exploration: Have students design a poster or comic strip showing how germs spread before and after Pasteur and Lister’s discoveries.

Key Vocabulary

Germs	Tiny living things, too small to see without a microscope, that can cause sickness and infection.
Hygiene	Practices and habits that help to keep people and places clean and prevent the spread of disease.
Microscope	A scientific tool that makes very small objects appear much larger so they can be seen and studied.
Infection	A condition caused when harmful germs enter the body and multiply, making a person ill.
Sterilization	The process of killing all germs on an object or surface, often using heat or chemicals like carbolic acid.