Why is the genetic code described as degenerate, and what does the wobble hypothesis propose?

Why is the genetic code described as degenerate, and what does the wobble hypothesis propose?

• A. Most amino acids are encoded by more than one codon (degeneracy); wobble describes non-standard base pairing at the third codon position allowing tRNA to recognize multiple codons.
• B. The genetic code uses unique codons for each amino acid with no redundancy.
• C. Wobble refers to strict base pairing at all codon positions.
• D. Degeneracy means tRNA is rarely used in translation.

Answer: (A)

Most amino acids are encoded by more than one codon, so the genetic code is degenerate. This redundancy is shared mainly by the third nucleotide of the codon. The wobble hypothesis proposes that base pairing at this third position is flexible, allowing certain tRNA anticodons to recognize more than one codon. Because of these non-standard pairings, a single tRNA can bind multiple codons for the same amino acid, such as inosine in the anticodon pairing with A, U, or C in the codon, or G pairing with U in some cases. This flexibility explains why multiple codons can specify the same amino acid and why the code remains efficient and tolerant to mutations at the third base. The other statements don’t fit: the code isn’t unique with no redundancy, wobble isn’t strict base pairing at all positions, and degeneracy isn’t about tRNA being rarely used.

Most amino acids are encoded by more than one codon, so the genetic code is degenerate. This redundancy is shared mainly by the third nucleotide of the codon. The wobble hypothesis proposes that base pairing at this third position is flexible, allowing certain tRNA anticodons to recognize more than one codon. Because of these non-standard pairings, a single tRNA can bind multiple codons for the same amino acid, such as inosine in the anticodon pairing with A, U, or C in the codon, or G pairing with U in some cases. This flexibility explains why multiple codons can specify the same amino acid and why the code remains efficient and tolerant to mutations at the third base. The other statements don’t fit: the code isn’t unique with no redundancy, wobble isn’t strict base pairing at all positions, and degeneracy isn’t about tRNA being rarely used.