Across
- 3. a drug or chemical that kills bacteria cells
- 5. ability to defend against an infection
- 7. a foreign substance triggers an immune response
- 8. an immune system protein that defends against pathogens
- 9. an injection of dead or weakened pathogens that stimulates an active immune response
Down
- 1. change in a population over time
- 2. type of immunity that is long-lasting because the immune system produces its own antibodies
- 3. type of immunity that is temporary because antibodies are passed into the person
- 4. ability to survive or be immune to a chemical
- 6. main source of genetic variation