Across
- 2. Substance that stimulates immunity to a disease
- 4. Single-celled organisms without a nucleus
- 6. Molecule that carries genetic instructions
- 10. A community of organisms and their environment
- 11. A living thing
- 12. Change in a species over time
- 14. Unit of heredity passed from parent to offspring
- 15. The process by which plants make food using sunlight
- 16. Organelle that produces energy in the cell
- 19. Division process that results in two identical daughter cells
- 20. Small structure within a cell with a specific function
- 21. A variant form of a gene
Down
- 1. Basic unit of life
- 3. Green pigment used in photosynthesis
- 5. Process by which an organism becomes better suited to its environment
- 7. Chemical messenger in the body
- 8. Organelle that contains the cell's DNA
- 9. Molecule made of amino acids
- 13. A protein that speeds up chemical reactions
- 17. Long-term weather patterns in a region
- 18. Group of similar organisms that can breed and produce fertile offspring