History GCSE Medicine Edexcel KT3 L1 Germ Theory Industrial c1700-1900 (Fully Resourced).
This fully resourced lesson introduces students to Louis Pasteur’s Germ Theory of 1861 and how it revolutionised understanding of disease, replacing old ideas like miasma and Spontaneous Generation. No textbook required.

Lesson content (step by step):

Do Now / 5-a-day starter: retrieval quiz on the Great Plague (beliefs about causes, preventions, plague doctors, comparison to the Black Death). Students write full-sentence corrections.

Source task: students analyse Pasteur’s 1880 speech to the French Academy of Sciences (“I intend to extend the germ theory to the causes of certain common diseases”). They discuss what Germ Theory might be and why it was revolutionary.

Guided input: teacher-led reading and explanation of Pasteur’s four key ideas in Germ Theory:

Microbes (germs) exist all around us in the air.

Microbes cause decay and disease.

Microbes can be killed by heating (pasteurisation).

Microbes are not evenly distributed in the air.

Summary activity: pupils complete short tasks to show understanding of Spontaneous Generation vs Germ Theory (e.g. “10 words or less” definitions).

Factors analysis task: students are introduced to the wider context — scientific developments, technology (microscopes), the Scientific Revolution, demand for solutions to epidemics. They complete a table identifying which factors helped Pasteur develop, prove, or spread Germ Theory.

Explanatory writing: pupils write short “This meant that…” / “As a result…” sentences to show how each factor enabled Germ Theory.

Linking task: students add connections between factors (e.g. better microscopes made Pasteur’s experiments more convincing). They highlight which links were strongest.

Ranking activity: pupils rank seven factors in order of importance in enabling Germ Theory to be developed, explaining their reasoning.

Extended writing practice: scaffolded exam-style paragraph: “What was the biggest reason Germ Theory was developed in 1861?” Success criteria provided (factor named, evidence, explanation, comparison to others, clear judgement).

Plenary interpretation: students evaluate Anne Hardy’s interpretation — “Pasteur’s germ theory was the single most important turning point in the history of medicine.” They decide whether they agree, using evidence from the lesson.