The amino acids coded by a single codon areGroup of answer choicesMet and TyrMet and TrpTrp and TyrCys and TyrCys and Met

To determine which amino acids are coded by a single codon among the given options, we need to know the genetic code, which consists of codons (three-nucleotide sequences) that correspond to specific amino acids.

1. Identify Amino Acids:

   • Methionine (Met) is coded by the codon AUG.
   • Tryptophan (Trp) is coded by the codon UGG.
   • Tyrosine (Tyr) is coded by the codons UAU and UAC.
   • Cysteine (Cys) is coded by the codons UGU and UGC.

2. Analysis of Each Option:

   • Met and Tyr: Met is coded by a single codon (AUG), while Tyr is coded by two (UAU and UAC).
   • Met and Trp: Both Met (AUG) and Trp (UGG) are coded by single codons.
   • Trp and Tyr: Trp is coded by a single codon, Tyr is not.
   • Cys and Tyr: Cys is not a single codon (two codons), and neither is Tyr.
   • Cys and Met: Met is a single codon, while Cys is coded by two.

3. Conclusion: The only pair among the given choices that consists of amino acids where both are coded by a single codon is Met and Trp.

Final Answer

Met and Trp.