Across
- 2. A protein that the body produces to defend against infection
- 4. Diphtheria or tuberculosis, for example
- 7. A tiny disease-causing agent
- 8. Chemical poisons
- 9. A one-celled organism without a nucleus
Down
- 1. One-celled organisms without a nucleus that feed on organic matter, living or dead
- 2. A substance designed to stop bacteria from growing and reproducing
- 3. A substance designed to produce immunity to a disease
- 5. The body's general defense against disease
- 6. One-celled, chlorophyll-containing organisms without a nucleus