A mutation changes the codon UCA to UCG in an mRNA, and both codons code for serine. This is best described as:
Answer and explanation
Correct answer: D. A silent mutation
- Step 1: Compare the amino acids: UCA and UCG both specify serine.
- Step 2: Several codons code for one amino acid (degeneracy), so the polypeptide is unchanged: a silent substitution.
Answer
a silent mutation.
Why not the others: Missense changes the amino acid; nonsense creates a stop codon; a frameshift needs an insertion or deletion not divisible by three.
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