Isotopes
The answer has to be 20 characters long so this is irrelevant.
I think the answer is b. wavelength (:
Answer:
Homeostasis involves maintaining a balance of several factors that make a cell healthy.
Explanation:
The cell membrane is a lipid bilayer that prevents that passage of water and ions. This allows cells to maintain a higher concentration of sodium ions out the outside of the cell.
RNA has great capability as a genetic molecule; it once had to carry on hereditary processes on its own. It now seems certain that RNA was the first molecule of heredity, so it evolved all the essential methods for storing and expressing genetic information before DNA came onto the scene.