AP BIOLOGY

Detailed explanation-1: -base substitution, called a “nonsense” mutation, results in a stop codon in a position where there was not one before, which causes the premature termination of protein synthesis and, more than likely, a complete loss of function in the finished protein.

Detailed explanation-2: -Stop codons are also called nonsense codons because they do not code for an amino acid and instead signal the end of protein synthesis. Thus, nonsense mutations occur when a premature nonsense or stop codon is introduced in the DNA sequence.

Detailed explanation-3: -Substitution mutations just switch out one or more bases for different ones. Substitution mutations can cause many kinds of mutations. Some of these include nonsense, missense, and silent mutations. All of these depend on whether or not the new base codes for an amino acid different than the original.

Detailed explanation-4: -Nonsense: A nonsense variant is another type of substitution. Instead of causing a change in one amino acid, however, the altered DNA sequence results in a stop signal that prematurely signals the cell to stop building a protein.

Detailed explanation-5: -A nonsense mutation refers to a base substitution in which the changed nucleotide transforms the codon into a stop codon.