1. I. Mutations A change in the genetic code
Mutagen: substance that causes a mutation
3 Types:
DNA
Chromosome
Non-DisJunction

2. 1. DNA Mutation
A. Point Mutation: change in a single base pair
THE DOG BIT THE CAT
THE DOG BIT THE CAR

3. B. Frameshift Mutation: 1. Single base is added or deleted
2. All other bases shift one spot
THE DOG BIT THE CAT
THE DGB ITT HEC AT? or
THE DOR GBI TTH ECA
How would this change the amino acid sequence? Need to know types of mutations. Silent mutation – change in DNA sequence but still codes for the same amino acid. Missense mutation – change in the DNA sequence changes a single amino acid. Nonsense – change in DNA sequence codes for a premature STOP sequence and the rest of the sequence is not translated

4. 2. Chromosome Mutations: a. Change in the chromosome b. Chromosome:
5 – 10 % DNA
90 – 95% protein
Need to know types of chromosome mutations (on next slide)

5. 1. Deletion: portion missing
c. 3 examples:
1. Deletion: portion missing
2. Inversion: portion inverted on chromosome
3. Translocation: portion moves to the other homologous chrom.
Chapter 12.4

6. 3. Non-Disjunction:
a. Failure of chrom to separate properly during meiosis
b. Incorrect number of chrom in egg/sperm
c. Examples:
Trisomy 21 (Down’s Syndrome)

7. http://images. google. com/images