Which statement describes redundancy in the genetic code?

Which statement describes redundancy in the genetic code?

• A. The code is nonredundant.
• B. Some amino acids have multiple triplet codes.
• C. Each triplet codes for a unique amino acid, with no overlaps.
• D. Triplets encode nucleotides instead of amino acids.

Answer: (B)

Redundancy in the genetic code means degeneracy: multiple codons (triplets of nucleotides) can specify the same amino acid. That’s why the statement describing redundancy best is that some amino acids have multiple triplet codes. In the genetic code, there are 64 possible codons but only 20 amino acids (plus stop signals), so many amino acids are encoded by more than one codon. For example, leucine, serine, and arginine each have six different codons, while others have four or fewer, and a couple are encoded by a single codon. This overlap helps protect proteins from small mutations and allows flexibility in reading the genetic message, often with the third base varying without changing the amino acid (the wobble effect). The other descriptions aren’t accurate: a nonredundant code would map each codon to a unique amino acid with no overlaps; and codons do not encode nucleotides themselves but amino acids (with stop codons marking termination).

Redundancy in the genetic code means degeneracy: multiple codons (triplets of nucleotides) can specify the same amino acid. That’s why the statement describing redundancy best is that some amino acids have multiple triplet codes. In the genetic code, there are 64 possible codons but only 20 amino acids (plus stop signals), so many amino acids are encoded by more than one codon. For example, leucine, serine, and arginine each have six different codons, while others have four or fewer, and a couple are encoded by a single codon. This overlap helps protect proteins from small mutations and allows flexibility in reading the genetic message, often with the third base varying without changing the amino acid (the wobble effect). The other descriptions aren’t accurate: a nonredundant code would map each codon to a unique amino acid with no overlaps; and codons do not encode nucleotides themselves but amino acids (with stop codons marking termination).