2. Genetic Disorders

3. Genetic Mutations Because DNA controls characteristics of a cell it must be copied before a cell reproduces Sometimes mistakes occur during this process These mistakes are called Mutations

4. Genetic Mutations Genetic mutations can be as little as one nucleotide that was incorrectly copied to whole genes that are missing or added Genetic mutations are more devastating when they occur in sex cells than body cells because they affect the development of an entire organism (because every cell that is generated gets the error)

5. Mutations Mutations can be: deleted genes, extra genes, disordered genes, or moved genes Most are neutral Eye color Birth marks Some are harmful Sickle Cell Anemia Down Syndrome Some are beneficial Sickle Cell Anemia to Malaria Immunity to HIV

6. Mutagenic Agents The most common cause of mutations is Mutagenic Agents Mutagenic agents include things like: Radiation, Temperature extremes, and Chemicals These agents alter the DNA code by interfering with DNA replication, and protein formation Sometimes it causes uncontrolled cell division (resulting in cancer)

7. Chromosome Mutations Chromosomal mutations: having extra chromosomes, missing chromosomes or broken pieces of chromosomes that attach or are lost can occur during meiosis or mitosis (ie: the chromosomes don’t split correctly) Can be caused by mutagenic agents

8. Chromosomal Mutations Cells with chromosomal mutations often do not survive because so much genetic information is missing If it occurs in egg or sperm cells, it can effect the new fertilized cell produced (often results in death)

9. Types of Disorders Recessive Disorder: person must receive a copy of the mutated gene from both parents to have disorder (eg: Sickle Cell Anemia) Dominant Disorder: person needs only one mutated gene to have the disorder (eg: Huntington’s Disorder)

10. Types of Disorders Cont’d X-Linked Disorder: mutated gene found on the X chromosome; more common in males than females because females have 2X chromosomes and males only have 1X (eg: Color blindness) Chromosomal Disorder: caused by having extra chromosomes (eg: Down’s Syndrome) Multi-factorial: Many genes are involved in the disorder (eg: Asthma)