If three bases are required to code for one amino acid, how many bases long must the gene be to encode a protein 400 amino acids long?

Answer :

The genetic code is the set of rules that defines how a nucleotide sequence in RNA is translated into an amino acid sequence in a protein. This code is common to all living beings (although there are small variations), which shows that it has had a unique origin and is universal, at least in the context of our planet.