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: -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.

Detailed explanation-3: -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-4: -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.

Detailed explanation-5: -A genetic mutation that does not cause a change in the amino acid sequence of the resulting protein can still alter the protein’s expected function, according to a new study conducted at the National Cancer Institute (NCI), part of the National Institutes of Health (NIH).