Key learning points

1. Some, but not all, bacteria are pathogens that can cause communicable diseases in humans.
2. Pathogenic bacteria produce toxins that damage living tissue and cause disease.
3. Salmonella food poisoning as an example of a bacterial disease, how it is spread, and how the spread can be reduced.
4. Viruses invade cells to reproduce where they cause damage to cells.
5. Influenza as an example of a viral disease, how it is spread, and how the spread can be reduced.

Common misconception

Keywords

• Bacteria - single celled prokaryote.

• Pathogen - a micro-organism that causes disease.

• Communicable disease - a disease that can be spread from person to person.

• Toxin - a poison made by bacteria.

• Virus - an infectious agent.