1. WHAT IS A MUTATION?
a change in the sequence Can affect one or many
of DNA nucleotides
Mutation
Point mutation Error in mitosis
Chromosomal mutation

2. TYPES OF MUTATIONS
Point Mutation
Chromosomal Mutation
(Substitution)
 Change in only 1  Change in MANY
nucleotide nucleotides – up to a
 Ex. whole chromosome
AATCCGGCG  Ex.
AAACCGGCG

3. TYPES OF MUTATIONS – PART 2
1. Deletion = nucleotides are removed
 Ex. AATCCGGCG
AATCGGCG
2. Insertion = nucleotides are added
 Ex. AATCCGGCG
AATCCGGCCG
3. Inversion = order of nucleotides is reversed
 Ex. AATCCGGCG
GCGGCCTAA
 Usually occurs with big pieces of chromosomes

4. NONDISJUNCTION
 Definition = when pairs of chromosomes don’t
correctly separate during meiosis
 Results = an imbalance of chromosomes