How many amino acids are encoded by a single 64 codon set?

The correct answer to the question regarding how many amino acids are encoded by a single 64 codon set is that 20 amino acids are represented by those codons.

In the genetic code, there are 64 possible codons (combinations of three nucleotides), but not every codon corresponds to a unique amino acid. Instead, there are 20 standard amino acids that are used to build proteins. The genetic code is degenerate, meaning that multiple codons can encode the same amino acid. For example, both the codons UUU and UUC code for the amino acid phenylalanine.

In addition to the amino acid encoding codons, there are specific codons that serve as stop signals in protein synthesis, which do not correspond to any amino acid. This is why the number of amino acids (20) is significantly lower than the total number of codons (64), as multiple codons can lead to the same amino acid, while others signify termination of translation.

Thus, when considering the entirety of the 64 codon set, it can be concluded that they collectively code for 20 amino acids.