Name _____________________________________
MUTATIONS
Period _____ Date ________________ Seat ______
Mutation: A change in the genetic material of a cell.
TYPES OF POINT MUTATIONS
Point mutation: A gene mutation in which a single
base pair in DNA has been changed.
Mutation comes from the Latin word mutare, meaning “
to change
.”
Before Mutations (normal)
Substitution
T AC C GAC T GAC GC GC T GA
G
A
A
T AC C GAC T GGC GC GC T GG
AUGGC UGAC UGUGC GAC U
AUGGC UGAC C GUGC GAC C
M
A
D
C
A
T
M
A
D
R
A
T
One base is changed to a different base
Frameshift mutation:
Insertion
T AC C GAC T GAC GC GC T GA
AUGAGC UGAC UGUGC GAC U
M
S
Stop
A new base is added to the DNA sequence
causing a frameshift to the right
Frameshift mutation:
Deletion
T AC GAC T GAC GC GC T GA
AUGC UGAC UGUGC GAC U
M
L
T
V
R
?
A base is removed from the DNA sequence
causing a frameshift to the left
Fun Fact: House cats can’t taste sweets because they have a 247 bp deletion in the Tas1r2 gene, resulting in a downstream stop codon.
1
G
Name _____________________________________
MUTATIONS
Period _____ Date ________________ Seat ______
Chromosomal mutation: A change in the number or
structure of a chromosome.
Mutagen: A chemical or physical agent in the
Environment that interacts with DNA and may cause a
mutation.
FOUR TYPES OF CHROMOSOMAL MUTATIONS
Examples of chemical mutagens:
Pesticides
Tobacco smoke
Pollutants
Examples of physical mutagens:
X-rays
Ultra violet light
Harmful mutation
Beneficial mutation
Sickle cell disease
normal
2
Lactose tolerance
abnormal