2. 1.Most genetic disorders result from a mutation in one gene. a.Mutation: a change in an organism’s genetic material (DNA) 2.A mutated gene produces a flawed protein that does not function properly or a protein that does not function at all. a.Examples of genetic disorders that are caused by the mutation of one gene: b.Hemophilia, sickle cell anemia, and cystic fibrosis. Normal blood cells Sickle- shaped blood cells

3. 1.Mutagens: environmental factors that can cause some mutations 2.Examples of mutagens: a.UV radiation b.Pollution c.Certain chemicals d.Viruses UV radiation can cause mutations. Viruses can cause mutations.

4. 1.Germ cells: cells that produce gametes (egg & sperm cells) 2.When an egg or sperm cell containing mutations combine to produce offspring, the mutation will be present in ALL of the offspring’s body cells.

5. 1. Body cell: any cell that is not a gamete, such as a skin or bone cell 2. Mutations happen in cells & build up over time 3. Most cancers are a result of a build up of mutated cells – after a while, there are so many mutated cells that they become cancerous (divide out of control)

6. Substitution 1.Base-Pair Substitutions: one base is replaced with the wrong letter a)Also called point mutations b)Examples: Some forms of cystic fibrosis Type B blood Sickle-cell anemia

7. 1.Silent mutation: a change in a base pair into another that codes for the same amino acid 2.Examples: a.Type B blood

8. 1.Missense Mutations: point mutation that still codes for an amino acid, just the wrong amino acid 2.May or may not be harmful

9. 1.Nonsense mutations: prematurely code for stop codon a)Result: a nonfunctional protein

10. Deletion 1.Deletion: one or more of the bases is deleted from the code a)Causes a shift in the reading frame b)Usually ends up causing a missense or a nonsense mutation.

11. Insertion 1.Insertion: one or more base pairs are inserted into the code a)Causes a shift in the reading frame b)Usually ends up making a missense or a nonsense mutation.