AP BIOLOGY

Detailed explanation-1: -Silent mutations occur when the change of a single DNA nucleotide within a protein-coding portion of a gene does not affect the sequence of amino acids that make up the gene’s protein.

Detailed explanation-2: -Point Mutations 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-3: -Silent mutations are mutations in DNA that do not have an observable effect on the organism’s phenotype. They are a specific type of neutral mutation. The phrase silent mutation is often used interchangeably with the phrase synonymous mutation; however, synonymous mutations are not always silent, nor vice versa.

Detailed explanation-4: -Point mutations that alter the resulting protein sequences are called nonsynonymous mutations, while those that do not alter protein sequences are called silent or synonymous mutations.

Detailed explanation-5: -Nonsense Mutation A nonsense mutation occurs in DNA when a sequence change gives rise to a stop codon rather than a codon specifying an amino acid. The presence of the new stop codon results in the production of a shortened protein that is likely non-functional.