Natural selection allows nature to chose which species survives. Only the fittest get to pass on their genes. And by fittest i mean the ones that are better adapted to the environment.<span />
If this answers your question:
Disaccharides are formed when 2 sugar molecules combine. An example of this is Maltose
Right amount of water is the secret.
That would be the concentration gradient of hydrogen ions(protons). See the attached pic:)
