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• Eye color• Birth marks

• Some are harmful• Sickle Cell Anemia• Down Syndrome

• Some are beneficial• Sickle Cell Anemia to Malaria• Immunity to HIV

Gene Mutations• Point Mutations – changes in one or

a few nucleotides– Substitution

• THE FAT CAT ATE THE RAT• THE FAT HAT ATE THE RAT

– Insertion• THE FAT CAT ATE THE RAT• THE FAT CAT XLW ATE THE RAT

– Deletion• THE FAT CAT ATE THE RAT• THE FAT 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

• THE FAT CAT ATE THE RAT• THE FAT HCA TAT ETH ERA T

– Deletion• THE FAT CAT ATE THE RAT• 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