DNA MUTATIONS

Causes There are two ways in which DNA can become mutated: Mutations can be inherited. Parent to child Mutations can be acquired. Environmental damage Mistakes when DNA is copied

EffecTS oF Mutations Most are neutral Some are harmful Eye color Birth marks Some are harmful Sickle Cell Anemia Down Syndrome Some are beneficial Sickle Cell Anemia for Malaria Immunity to HIV

Gene Mutations Point Mutations – changes in one or a few nucleotides Substitution (same number or bases) THE FAT CAT ATE THE RAT THE FAT HAT ATE THE RAT

SUBSTITUTION If a substitution changes the amino acid, it’s called a MISSENSE mutation. If a substitution does not change the amino acid, it’s called a SILENT mutation. If a substitution changes the amino acid to a “stop,” it’s called a NONSENSE mutation.

Gene Mutations Frameshift Mutations – shifts the reading frame of the genetic message so that the protein may not be able to perform its function. Insertion (extra nitrogen base) THE FAT CAT ATE THE RAT THE FAT HCA TAT ETH ERA T Deletion (one less nitrogen base) TEF ATC ATA TET GER AT H H

Which type of mutation is responsible for new variations of a trait? Insertion, Deletion, Substitution (Missense) Which type of mutation results in abnormal amino acid sequence? Insertion, Deletion, Substitution (Nonsense & Missense Which type of mutation stops the translation of the mRNA? NONSENSE Substitution