1. Mutations

2. Change / alteration to the DNA of an organism They may be good, bad or have no effect A plant that can better tolerate the cold (GOOD) A change that causes some syndrome or illness (BAD) A change that we never see or notice (NONE) A driving force behind evolution A plant that can better tolerate the cold (GOOD)

3. Causes of mutations Naturally occurring (they just happen) 2/3 of all cancers Mutagen – something in the environment that causes a change Examples: radiation (x-rays), pollution and toxic chemicals (Love Canal), smoking, diet, etc….

4. Types of mutations Genetic – causes a change in the gene May only effect one gene Change in the base (A,T, C, G) Chromosomal – causes a change in a chromosome or segments of a chromosome

5. Genetic mutations 1.Deletions: remove a base from the sequence ATCCGACAG (codons are in groups of 3) ATCGACAG 2.Insertions: a base is added to the sequence ATCCGACAG ATTCCGACAG These are both called frameshift mutations they cause a change in how the sequence is read

6. Types of genetic mutations 3. Substitutions: a base is changed (one is substituted for another) AGGCAA AGCCAA A substitution may not cause any change in the amino acid

7. Examples of genetic mutations Color blindness – x chromosome (sex linked) Hemophilia – x chromosome (sex linked) (free bleeding) Sickle cell – chromosome 11 (causes a change in the shape of red blood cells)

8. Chromosomal mutations Deletions – chromosome is deleted Duplication – chromosome is duplicated Inversion – chromosome is inverted Translocation – piece of a chromosome is moved to another chromosome (not homologous) Non-disjunction – chromosomes don’t separate properly

9. Examples of chromosomal mutations Downs syndrome – trisomy 21 (3 copies of the 21 chromosome total of 47 chromosomes) Turner’s syndrome – x or piece of the x chromosome is missing (45 chromosomes) Klinefelter’s syndrome – xxy (47 chromosomes an extra x chromosome)