Across
- 5. A microscopic living thing, such as bacteria or viruses.
- 7. A substance used to kill or stop the growth of bacteria.
- 12. The process by which plants use sunlight to make food.
- 13. A substance that stimulates the immune system to fight specific pathogens.
- 15. A threadlike structure of DNA found in the nucleus.
- 16. The basic unit of life in all living organisms
- 17. The molecule that contains genetic instructions for life.
- 19. The movement of water across a selectively permeable membrane.
- 20. Selection The process by which organisms better adapted to their environment survive and reproduce.
Down
- 1. The "powerhouse" of the cell; it produces energy.
- 2. A change in the DNA sequence.
- 3. System The body’s defense system against infections and diseases.
- 4. The process of breaking down food to release energy.
- 6. A trait that helps an organism survive and reproduce in its environment.
- 8. A group of similar cells working together to perform a function.
- 9. Any organism that causes disease.
- 10. A segment of DNA that codes for a trait.
- 11. The organelle that contains the cell's DNA.
- 14. The ability of an organism to maintain a stable internal environment.
- 18. System A group of organs that work together to perform major functions.