Question

Which of the following amino acids is coded by only single codon?

• A. Tyrosine
• B. Phenylalanine
• C. Tryptophan
• D. Isoleucine

Answer 1

Answer: (C)

The amino acid tryptophan is coded solely by a single codon of UGG. Tyrosine is coded by two different codons: UAU and UAC, phenylalanine is coded by two codons: UUU and UUC, and isoleucine is coded by 3 codons: AUU, AUC and AUA.