1. Mutation Notes
Chapter 12-4

2. I. Mutations A. Changes or mistakes in genetic material (DNA)
1. Some are good and some are bad
a) Good: make new traits
b) Bad: change a protein structure or gene activity=disease

3. B. Mutations can occur during Cell Division (s-phase)
1. Mistakes during DNA Replication

4. C. Can happen in Body Cells or Sex Cells
1. Mutations can happen during Mitosis (making of body cells)
2. The mutation only affects the person, not the offspring
2. affects the function of the cell
a) Example: It causes the cell to not stop reproducing (cancer)

5. 2. Mutations can occur during meiosis
a) Meiosis is the making of gametes (sperm or eggs)
b) These mutations affect the offspring not the person

6. II. Types of Mutations
A. Point Mutation: a change in a single base pair in DNA.
1. May cause change in one single amino acid or causes no change at all.

7. 2. Substitution: when a single nucleotide is changed
Ex:
AUG AAG UUU GGC GCA UUG UAA
met lys phe gly ala leu stop
AUG AAG UUU _GC GCA UUG UAA
met lys phe ___ ala leu stop

8. B. Frameshift Mutation: mutations that cause a change in the entire amino acid sequence following the location of mutation.
1. Deletion: when a single nucleotide is removed from DNA.

9. Ex:
AUG AAG UUU GGC GCA UUG UAA
met lys phe gly ala leu stop
AUG AAG UUG GCG CAU UGU AA
met lys ___ ___ ___ ___ ___

10. 2. Insertion: when a single nucleotide is inserted somewhere.
AUG AAG UUU GGC GCA UUG UAA
met lys phe gly ala leu stop
AUG AAG UUU GGC AGCA UUG UAA
met lys phe gly ___ ___ ___

11. C. Chromosomal Mutations: Changes in number or structure of chromosomes.
1. Deletion or duplication of a piece of chromosome.
a) depending on the information disrupted or lost will determine the effect of the mutation.

12. 2. Inversion: a piece of the chromosome will detach and reattach in reverse order.
3. Translocation: a piece of a chromosome will break off and reattach to an entirely different chromosome.

13. III. Causes of Mutations
A. Mistakes during the cell cycle (DNA Replication)
B. Mistakes during Protein synthesis (transcription or translation)
C. Mutagens: any agent that causes a mutation
1. Ex: radiation, chemicals, high temperatures, etc.