AP BIOLOGY

Detailed explanation-1: -(MIS-sens myoo-TAY-shun) A genetic alteration in which a single base pair substitution alters the genetic code in a way that produces an amino acid that is different from the usual amino acid at that position. Some missense variants (or mutations) will alter the function of the protein. Also called missense variant.

Detailed explanation-2: -Missense Mutation A missense mutation is a DNA change that results in different amino acids being encoded at a particular position in the resulting protein.

Detailed explanation-3: -Missense mutations occur when a single nucleotide base in a DNA sequence is swapped for another one, resulting in a different codon and, therefore, a different amino acid. These mutations are quite common and, in most cases, they don’t affect the overall shape and function of the protein.

Detailed explanation-4: -Missense mutations may retain function, depending on the chemistry of the new amino acid and its location in the protein. Nonsense mutations produce truncated and frequently nonfunctional proteins. A frameshift mutation results from an insertion or deletion of a number of nucleotides that is not a multiple of three.

Detailed explanation-5: -Missense codons (missense mutations): A change in a single amino acid that results from a point mutation in the DNA sequence. Nonsense codons (nonsense mutations): The conversion of a codon from one that encodes an amino acid to one that acts as a stop codon due to a point mutation in the DNA sequence.