Germs and Immunity
Map
Arrows point from what you learn first to what it opens. Point at a concept to light up its chain and where it comes back deeper. Right-click a concept (or press and hold it) for its lessons and stories.
- Proven to depth123
- Open
- Locked
- Comes back deeper
Learning path
In the order the concepts build on each other.
- MicrobesReadyLiving things too small to see without a microscope: bacteria, viruses, fungi and parasites. Most are harmless and many are useful; only a few, called germs, make people ill. A typical adult carries roughly as many bacteria as body cells.
- Antibiotic resistanceLockedAntibiotics kill bacteria or stop them growing, but they don't work on viruses such as colds and flu. Each time antibiotics are used, bacteria that happen to survive can multiply, until the medicine stops working. Taking them only when prescribed, exactly as prescribed, keeps them working.Opens after: Microbes
- How germs spreadLockedGerms travel through the air, by touch, in food and water, by insect bites and through blood. Washing hands with soap for at least 20 seconds, hand gel when there is no sink, and catching coughs in a tissue or elbow block some of the busiest routes.Opens after: Microbes
- Immune systemLockedEverything in the body that fights germs: barriers (skin, mucus, stomach acid), a fast general defence (inflammation and white blood cells that swallow germs), a slower targeted one (antibodies that stick to one germ), and immune memory that makes the next fight faster. A fever is usually part of the defence.Opens after: Microbes
- VaccinesLockedA vaccine shows the immune system a harmless version of a germ - killed or weakened, a piece of it, or instructions for the body's cells to make that piece - so it learns to recognise the germ without the illness. When enough people are immune, a germ can't spread (community immunity), which protects those who can't be vaccinated.Opens after: Immune system