In a certain gene, a point mutation changes a codon in the mRNA from UUU to UUC. Despite this mutation, no change occurs in the sequence of amino acids in the resulting protein. Explain why.

• A. The mutation from UUU to UUC introduces a stop codon, but it occurs at the end of the gene so the protein sequence remains unchanged.
• B. UUU and UUC are start codons, so changing between them doesn't affect the amino acid sequence of the protein.
• C. The mutation from UUU to UUC changes the amino acid from Phenylalanine to Leucine, but this change doesn't affect the protein's function.
• D. The mutation from UUU to UUC is a synonymous mutation, as both codons code for the same amino acid (phenylalanine), due to the redundancy of the genetic code.

Answer: (D)