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