AP BIOLOGY

Detailed explanation-1: -A nucleotide change in the DNA that does not result in an amino acid change in the protein is called a “synonomous” or “silent” mutation (see Figure 3.3).

Detailed explanation-2: -So, the correct answer is ‘Silent mutation’.

Detailed explanation-3: -Silent: If abase substitution occurs in the third position of the codon there is a good chance that a synonymous codon will be generated. Thus the amino acid sequence encoded by the gene is not changed and the mutation is said to be silent.

Detailed explanation-4: -Silent mutations lead to a change of one of the letters in the triplet code that represents a codon, but despite the single base change, the amino acid that is coded for remains unchanged or similar in biochemical properties. This is permitted by the degeneracy of the genetic code.

Detailed explanation-5: -Silent mutations are mutations, or changes, to a gene’s DNA sequence that have no effect on the amino acid sequence coded for by that gene; they are called silent because their effect cannot be heard.