A codon substitution that does not change the amino acid due to redundancy is called

A codon substitution that does not change the amino acid due to redundancy is called

• A. Missense mutation
• B. Nonsense mutation
• C. Silent mutation
• D. Frameshift mutation

Answer: (C)

Redundancy in the genetic code means that multiple codons can specify the same amino acid. When a nucleotide change occurs but the same amino acid is still incorporated, the resulting protein sequence remains unchanged. This is called a silent mutation (a synonymous substitution). Often the change occurs in the third base of a codon due to wobble in base pairing, so codons like GGU, GGC, GGA, and GGG all code for glycine; altering one nucleotide may not alter the amino acid. Silent mutations generally do not affect the protein, though they can occasionally influence gene expression or mRNA stability through codon usage or mRNA structure. In contrast, a missense mutation changes an amino acid, a nonsense mutation creates a premature stop, and a frameshift mutation shifts the reading frame, significantly altering the protein sequence.

Redundancy in the genetic code means that multiple codons can specify the same amino acid. When a nucleotide change occurs but the same amino acid is still incorporated, the resulting protein sequence remains unchanged. This is called a silent mutation (a synonymous substitution). Often the change occurs in the third base of a codon due to wobble in base pairing, so codons like GGU, GGC, GGA, and GGG all code for glycine; altering one nucleotide may not alter the amino acid. Silent mutations generally do not affect the protein, though they can occasionally influence gene expression or mRNA stability through codon usage or mRNA structure. In contrast, a missense mutation changes an amino acid, a nonsense mutation creates a premature stop, and a frameshift mutation shifts the reading frame, significantly altering the protein sequence.