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

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

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

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

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

9. 4. Nondisjunction – failure of homologous chromosomes to separate properly during meiosis Two possible outcomes:
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. 7.4 Human Genetics and Pedigrees
KEY CONCEPT A combination of methods is used to study human genetics.

11. 7.4 Human Genetics and Pedigrees
Pedigree – family record that shows how a trait is inherited over several generations

12. Ex: Autosomal  Hh Sex-linked  XHXh 7.4 Human Genetics and Pedigrees
Circles  Girls
Squares  Boys
Carrier – individual with one copy of a recessive allele
Usually do not express the trait but can pass it along to offspring
½ colored in
Ex: Autosomal  Hh
Sex-linked  XHXh

13. 7.4 Human Genetics and Pedigrees

14. 7.4 Human Genetics and Pedigrees
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

15. Detecting Human Genetic Disorders
7.4 Human Genetics and Pedigrees
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 14th
and 16th week of pregnancy

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

17. 5.3 Regulation of Cell Cycle
Cancer
Tumor – abnormal group of cells that result from uncontrolled cell division
Growth factors – proteins that bind to cells and stimulate cell division

18. 5.3 Regulation of Cell Cycle
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
cancer cell
bloodstream
normal cell

19. Kinds of Cancer – based on types of tissue that affect
5.3 Regulation of Cell Cycle
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

20. 5.3 Regulation of Cell Cycle
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

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

22. Oncogenes – gene that causes cancer
5.3 Regulation of Cell Cycle
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

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

24. 5.3 Regulation of Cell Cycle
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
And lowering exposure to carcinogens (tobacco, UV rays)

25. How do Cancer cells behave differently from Healthy ones