Across
- 3. Microscopic, unicellular organisms
- 4. The gas that is used in the body to create energy
- 5. Responsible for pumping blood around the human body
- 6. A bacteria that causes disease
- 7. An organ in the body where oxygen and carbon dioxide exchange occurs
Down
- 1. Treatment with a vaccine to produce immunity against a disease
- 2. Anything that stops your body working properly