In this passage they talking about water problem and flood, flooding means the covering or submerging of normally dry land with a large amount of water. it means that water is useful but it also dangerous.
They allow for many variations to exist in species. That's the answer
1. tRNA - Brings in amino acids according to the codons and adds them to the growing protein.
2. rRNA - Forms the ribosome where the mRNA is read.
3. mRNA - Acts as a messenger between the DNA in the nucleus and the ribosome in the cytosome
Gamma-amino-butyric acid (GABA)