1. Gene Mutations
Chapter 11

2. DNA and Chromosomes Prokaryotes: Eukaryotes:
DNA found in cytoplasm (no nucleus) as large, single molecule
Eukaryotes:
DNA in nucleus on many chromosomes (human = 46)
DNA length - 1,000x’s longer than cell diameter (must be folded)

3. Mutations Mutation: changes in genetic material
Can occur on single gene, or entire chromosome
Causes:
1) Chance
2) Mutagens: factors that change DNA (i.e.: UV light, cigarette tar, radiation, etc.)

4. Gene Mutations 2 Types of Gene Mutations:
1) Point Mutations: occur at single point
-may result in no change at all OR a genetic disorder (sickle-cell anemia)
Substitution: 1or more nucleotides replaces another
a) Silent- doesn’t change the amino acid
b) Missense- changes the amino acid
c) Nonsense- changes amino acid to “stop”
Original DNA →
Mutated DNA →

5. THE DOG BIT THE CAT
THE DOG HIT THE CAT
THE DOG HIT THE CAR
THE GOG HIT THE CAR

6. Gene Mutations
2) Frameshift Mutations: shift in protein sequence; can ruin protein
-result is usually devastating
Insertion: 1or more nucleotides added
Deletion: 1or more nucleotides removed
Original DNA →
Mutated DNA →
Original DNA →
Mutated DNA →

7. THE DOG BIT THE CAT
THE DOB ITT HEC AT