Revision notes
Core ideas
Secure these ideas first. Say each definition in your own words, then connect it to the topic overview.
- Four Humours: The ancient theory that illness resulted from an imbalance of blood, phlegm, black bile and yellow bile.
- Germ theory: Pasteur's explanation that microorganisms cause decay and disease, developed in the nineteenth century.
- Vaccination: Using a safe form or component of a pathogen to stimulate immunity against disease.