Shown below are several amino acid substitutions in the α and β chains of human hemoglobin...

Shown below are several amino acid substitutions in the α and β chains of human hemoglobin:

Using the code table (Figure), determine how many of them can occur as a result of a single-nucleotide change.

Figure

The coding dictionary. AUG encodes methionine, which initiates most polypeptide chains. All other amino acids except tryptophan, which is encoded only by UGG, are represented by two to six triplets. The triplets UAA, UAG, and UGA are termination signals and do not encode any amino acids.