Step 1: Genetic Code Comprehension.
The genetic code dictates how nucleotide sequences in mRNA translate to amino acids. A triplet of nucleotides, known as a codon, specifies a particular amino acid.Step 2: Phenylalanine Codon Identification.
The codons responsible for coding the amino acid phenylalanine (\(Phe\)) are:\[\text{UUU and UUC}.\]From the provided choices, \(UUU\) is the accurate codon for phenylalanine.Step 3: Analysis of Alternative Options.
Option (A): AUG. Invalid. AUG functions as the start codon and encodes methionine. Option (B): UUU. Valid. UUU encodes phenylalanine. Option (C): GCA. Invalid. GCA encodes alanine. Option (D): CCC. Invalid. CCC encodes proline.Step 4: Final Determination.
The designated codon for phenylalanine is \(UUU\).\[\therefore \text{The correct answer is: (B)}.\]