Mutations

Mutation

A heritable change in the DNA sequence of an organism.

Mutant

An organism resulting from a mutation with a recognizable change in phenotype compared to the wild type.

Wild Type

The phenotype most commonly observed in nature.

Point Mutation

A mutation affecting only one or a few nucleotides in a gene.

Silent Mutation

A point mutation that results in the same amino acid being incorporated into the resulting polypeptide, having no effect on the protein's structure.

Missense Mutation

A mutation that results in a different amino acid being incorporated into the resulting polypeptide.

Nonsense Mutation

A point mutation that converts a sense codon to a stop codon, resulting in shorter and typically nonfunctional proteins.

Frameshift Mutation

A mutation caused by insertions or deletions of nucleotides that are not in multiples of three, leading to a shift in the reading frame.

Proofreading

A DNA replication mechanism in which DNA polymerase corrects mistakes by replacing incorrect bases.

Ames Test

A rapid screening method using bacteria to determine the carcinogenic potential of new chemical compounds.