What term describes repetition or redundancy in the genetic code?

• A. Degeneracy
• B. Redundancy
• C. Palindrome
• D. Mutation

Answer: (A)

Degeneracy describes this repetition or redundancy in the genetic code: more than one codon can specify the same amino acid. For example, phenylalanine is encoded by UUU and UUC; leucine is encoded by six different codons, and serine and arginine each have six as well. This means a change in the third base of a codon often does not alter the amino acid, which helps buffer against mutations and contributes to the code’s robustness. Redundancy is a related idea, but degeneracy is the precise term used for this codon-to-amino-acid equivalence. Palindrome and mutation refer to other concepts entirely—sequence symmetry and sequence change respectively.