The genetic code is degenerate, meaning?

The genetic code is degenerate, meaning?

• A. A codon encodes more than one amino acid
• B. A single amino acid can be encoded by more than one codon
• C. Only rarely does a single codon specify an amino acid
• D. Genes encode tRNA molecules

Answer: (B)

The idea being tested is that the genetic code is degenerate, meaning multiple codons can specify the same amino acid. There are 64 possible codons but only about 20 amino acids (plus stop signals), so several different triplets map to the same amino acid. This redundancy—synonymous codons—helps protect against changes in the genetic sequence and often allows the third base in a codon to vary without changing the amino acid actually incorporated. For example, leucine is encoded by six different codons. In contrast, a codon does not encode more than one amino acid, and genes mainly encode proteins or functional RNAs rather than tRNA itself.

The idea being tested is that the genetic code is degenerate, meaning multiple codons can specify the same amino acid. There are 64 possible codons but only about 20 amino acids (plus stop signals), so several different triplets map to the same amino acid. This redundancy—synonymous codons—helps protect against changes in the genetic sequence and often allows the third base in a codon to vary without changing the amino acid actually incorporated. For example, leucine is encoded by six different codons. In contrast, a codon does not encode more than one amino acid, and genes mainly encode proteins or functional RNAs rather than tRNA itself.