1. 8.7 Mutations KEY CONCEPT Mutations - changes in DNA that may or may not affect phenotype

2. 8.7 Mutations When: can mutations occur Caused by errors during: Replication, transcription, cell division, or by external factors Where: can mutations occur Germ-cell mutation – occurs in a gamete Somatic mutation – occurs in a body cell Who: can mutations affect Germ-cell  Does not affect the individual but may be passed on to offspring Somatic  Will affect the individual but are not passed on to offspring

3. 8.7 Mutations Lethal Mutations Cause death, often before birth Silent Mutations Have no effect on phenotype What: is mutated Gene Chromosome

4. 8.7 Mutations Gene Mutations 1.Point mutation – substitutes, adds or deletes a single nucleotide Generally mutations that affect a single gene happen during replication mutated base

5. 8.7 Mutations Gene Mutations 2. Frame Shift Mutation Deletion & addition point mutation cause the remaining codons to be incorrectly grouped

6. 8.7 Mutations

7. Chromosome Mutations 1.Deletion – loss of a piece of a chromosome due to chromosomal breakage 2.Inversion – chromosomal segment breaks off and then reattaches in reverse order to the same chromosome –Orig: ATAGCTA –Inv:ATCGATA 3.Translocation – chromosome piece breaks off and reattaches to another non-homologous chromosome

8. 8.7 Mutations

9. 4. Nondisjunction – failure of homologous chromosomes to separate properly during meiosis Two possible outcomes: 1.Trisomy - Three copies of chromosome One gamete has two copies Zygote = 3 copies of chromosome 2. Monosomy - One copy of chromosome One gamete has no copies Zygote - 1 copy of chromosome

10. 8.7 Mutations KEY CONCEPT A combination of methods is used to study human genetics. 7.4 Human Genetics and Pedigrees

11. 8.7 Mutations Detecting Human Genetic Disorders Genetic screening – Examination of a person’s genetic makeup Genetic counseling – Medical guidance that informs about possible problems that could affect their offspring Prenatal testing Amniocentesis – Removes a small amount of amniotic fluid between the 14 th and 16 th week of pregnancy 7.4 Human Genetics and Pedigrees

12. 8.7 Mutations Chorionic villi sampling Physician obtains a sample of the chorionic villi Tissue that grows between the mothers uterus and the placenta Between the 8 th and 10 th week of pregnancy 7.4 Human Genetics and Pedigrees

13. 8.7 Mutations Karyotypes can show changes in chromosomes. –Deletion of part of a chromosome or loss of a chromosome –Some translocation changes in chromosomes –Extra chromosomes or duplication of part of a chromosome 7.4 Human Genetics and Pedigrees

14. 13.1 Ecologists Study Relationships Pedigree – Family record that shows how a trait is inherited over several generations 7.4 Human Genetics and Pedigrees

15. 8.7 Mutations Pedigrees Circles  Girls Squares  Boys Carrier – Individual with one copy of a recessive allele (heterozygous) Usually do not express the trait but can pass it along to offspring ½ colored in Ex: Autosomal  Hh Sex-linked  X H X h 7.4 Human Genetics and Pedigrees

16. 8.7 Mutations 7.4 Human Genetics and Pedigrees

17. 13.1 Ecologists Study Relationships Cancer Tumor – Abnormal group of cells that result from uncontrolled cell division Growth factors – Proteins that bind to cells and stimulate cell division 5.3 Regulation of Cell Cycle

18. 8.7 Mutations cancer cell bloodstream normal cell –Benign - Tumors remain clustered and can be removed. –Malignant - Uncontrolled dividing cells invade and destroy healthy tissues elsewhere in the body –Metastasize - Spread of cancer cells beyond their original site 5.3 Regulation of Cell Cycle

19. 8.7 Mutations Kinds of Cancer – Based on types of tissue that affect Carcinomas – Grow in the skin and tissues that line organs. Ex: lung cancer & breast cancer Sarcomas – Grow in bone and muscle tissue Lymphomas – Solid tumors that grow in the tissues that form blood cells –Leukemia – Tumors that form in blood-forming tissue – Over production of white blood cells 5.3 Regulation of Cell Cycle

20. 8.7 Mutations Causes of Cancer Mutagen – Cause mutations to occur within a cell that leads to cancer Carcinogen – Substance that increases the risk of developing cancer –Ex: tobacco, asbestos, X-rays, or UV rays from sun 5.3 Regulation of Cell Cycle

21. 8.7 Mutations Standard cancer treatments typically kill both cancerous and healthy cells. 5.3 Regulation of Cell Cycle

22. 8.7 Mutations Oncogenes – Gene that causes cancer Proto-oncogene – Normal gene that control cell’s growth. –When mutated  Oncogene Tumor-suppressor gene – Code for proteins to prevent uncontrolled cell division. –When mutated  Cancer 5.3 Regulation of Cell Cycle

23. 8.7 Mutations Viruses & Cancer Viruses can stimulate uncontrolled cell division Cause mutations in proto-oncogenes & tumor suppressor genes 5.3 Regulation of Cell Cycle

24. 8.7 Mutations Cancer Prevention Diet high in fiber and low in fat Fruits & vegetables are high in fiber Vitamins & minerals: carotenoids, vitamins A, C, and E, and calcium Daily exercise Lower exposure to carcinogens (tobacco, UV rays) 5.3 Regulation of Cell Cycle

25. 8.7 Mutations How do Cancer cells behave differently from Healthy ones http://www.youtube.com/watch?v=BmFEoCFDi- w&list=PLJicmE8fK0Ehrg3meytY7DT8LJiwuU3Th&index =92http://www.youtube.com/watch?v=BmFEoCFDi- w&list=PLJicmE8fK0Ehrg3meytY7DT8LJiwuU3Th&index =92