Across
- 2. outer layer of the earth
- 3. The major organ is the heart
- 4. discovered sea floor spreading
- 6. Discovered continental drift
- 13. A substance that takes part in and undergoes change during a reaction
- 14. having two different alleles or genes
- 15. When two or more atoms join together
- 16. only found on continent coast lines
Down
- 1. removes waste from the body
- 2. made of iron and nickle
- 5. processes food by breaking it down
- 7. part of the upper mantle
- 8. Attached to bones by tendons
- 9. having two of the same alleles
- 10. the continents seem to fit together like puzzle pieces
- 11. A substance produced during a chemical reaction
- 12. thickest layer of the earth