Which statement best describes the wobble hypothesis in genetic decoding?

• A. The third base of codon can pair with nonstandard bases in anticodon.
• B. All three bases in codon pair flexibly with anticodon.
• C. Wobble refers to energy savings in tRNA charging.
• D. Wobble only occurs in eukaryotes.

Answer: (A)

The wobble hypothesis shows that decoding the genetic code isn’t rigid at the third position of the codon. In translation, the tRNA anticodon can pair with the codon in a way that the third base of the codon forms nonstandard contacts with bases in the anticodon. This flexibility lets a single tRNA recognize multiple codons that encode the same amino acid, which helps explain why there aren’t 61 distinct tRNAs for every codon. For example, the anticodon may include inosine, which can pair with several different bases in the codon, expanding pairing options at the third position.

This is why the statement describing the third base of the codon pairing with nonstandard bases in the anticodon is the best fit. It’s not about all three bases pairing flexibly, it’s specifically about the third position enabling noncanonical interactions. It’s not about energy savings in tRNA charging, and wobble is a feature seen across many organisms, not restricted to eukaryotes.