Which of the Following Nucleotide Triplets Best Represents a Codon

Question

Which of the following nucleotide triplets best represents a codon?
A) a triplet separated spatially from other triplets
B) a triplet that has no corresponding amino acid
C) a triplet at the opposite end of tRNA from the attachment site of the amino acid
D) a triplet in the same reading frame as an upstream AUG
E) a sequence in tRNA at the 3' end

Accepted Answer

A codon is a three-letter nucleotide sequence in DNA/RNA that specifies an amino acid or starts/stops protein synthesis. It is read in triplets, and the reading frame is crucial in determining which amino acid will be added to the growing polypeptide chain. Therefore, a triplet in the same reading frame as an upstream AUG (start codon) is the best representation of a codon.