How Communicable Diseases Spread
Bacteria, viruses, fungi and protists spread through air, water, direct contact or a vector, and each route points at a different way to break the chain. Uses named human and plant diseases.
What a learner can do afterwards
- Sorts named diseases by pathogen type and by route of spread.
- Explains why a virus needs a host cell to reproduce while most bacteria do not.
- Picks a control measure that matches a given route of transmission and says why it works.
1 · Read
Four pathogen types cause communicable disease: bacteria, viruses, fungi and protists. Bacteria are single cells that mostly reproduce alone. A virus cannot reproduce without a host cell, since it must hijack the cell to copy itself.
Germs move by routes. Coughs launch some through the air, dirty water carries others such as cholera, touch passes colds, and vectors ferry germs between hosts. A vector is a living carrier such as a mosquito, which spreads malaria when it feeds.
Each route points at its own block. Masks and ventilation block airborne spread, clean water blocks waterborne spread, handwashing and isolation block touch, and bed nets block mosquito vectors. Match the block to the route and say why it works: it cuts the exact path the germ travels.
Answer in two steps. Name the route the germ uses, then pick the control that cuts that route. If the question names malaria, the route is a mosquito vector and the answer involves nets or draining breeding sites.
Name the pathogen and its route, then cut that exact route to stop the spread.
2 · Watch
Take it off screen
Where it sits
Where this leads
Jobs that lean on this skill. Follow one to see everything it is built on.
8 questions wait behind this lesson, each with its answer explained. Every answer feeds the sky: stars light as they are learned, and dim when it is time to come back.