Suppose that part of an amino acid sequence of a protein changed from tyrosine-proline-glycine-alanine to tyrosine-histidine-glycine-alanine. This change was most likely caused by a point mutation called a substitution.
Step-by-step explanation:
Any protein is synthesized by joining a number of amino acids together. This amino acid is placed based on the sequences of the DNA , for every 3 sequence there is an amino acid that is synthesized and therefore it is called as a triplet codon, since there may be many sequence for a single amino acid we call it as degenerate codon.