Pathogens

3. Introducing small quantities of dead/inactive pathogens into the body to stimulate an immune response & develop immunity.
5. An antibody formed in response to and capable of neutralizing a specific toxin from an invading pathogen.
7. Resistant to a particular infection or toxin owing to the presence of specific antibodies or sensitized white blood cells.
8. A type of white blood cell that defends the body against infection.
9. disease A disease which is infectious and can be spread through contact, water or air.
10. blind trial A drug trial in which neither patient nor doctor knows if the patient is receiving the new drug or placebo.
13. An organism, often a biting insect or tick, that transmits a disease/parasite from one animal/plant to another e.g. malaria.
14. Any microorganism that causes disease.

1. Drug that destroys bacteria inside the body without damaging human cells.
2. The process by which a cell, such as a white blood cell, engulfs/ingests microorganisms, other cells, & foreign particles.
4. Respond to specific antigens by combining with substances foreign to the body, e.g. viruses to help destroy them.
6. A substance used in clinical trials which does not contain any drug at all.
11. fission The asexual method bacteria reproduce through copying genetic material & division into two identical daughter cells.
12. The unique protein on the surface of a cell. Recognised by the immune system as ‘self’ or ‘non-self’.