This is extremely vague, but assuming this is regarding concentration gradient in the nervous system, the Sodium-Potassium pump is responsible for transporting sodium and potassium.
The most important acid deoxyribonucleic acid, or DNA, which carries the genetic code of any organism it, and the way that it transmits the individual characters in the life without this acid, or genetic code world would not exist :)
I hope you understand what I mean :)
The is answer is:
1. first to document careful observations of different cell types
2. A. Rubber is a conductor and transfers electricity from the wire.
3. B. Changing tides.
4. B. The fossils may have been moved by man, animals, or Earth's constructive and destructive processes.
5. A. They are produced by drought.
6. C. Stores heredity information.
7. D. Magnets have a set strength , while the strength of an electromagnet can be adjusted.
8. A. Temporary dam.
9. B. Invertebrates.
10. C. Human feces.
11. No answer.
12. A. Gas.
13. C. Increase the number of coils of copper he puts around the nail.
14. A. Sam is correct. It is not a physical change.
15. C. Landslides.
