Answer: The answer is - Based on the number of known amino acids and the number of known nucleotide bases
Explanation:
According to Francis Crick's calculation, three (3) nucleotides encode an amino acid. Proteins are built from a basic set of 20 amino acids, however there are only four (4) bases. Calculations therfore show that to encode at least twenty (20) amino acids a minimum of three (3) bases is required. Genetic experiments have shown that an amino acid is in fact encoded by a group of three (3) bases or codon.