1. Chapter 8 Chapter 8 Mendel and Heredity

2. Chapter 8 Objective: Learn the experiment Mendel performed that led to the modern science of genetics, pp. 162-165 Bio 6 d, h BIO.6The student will investigate and understand common mechanisms of inheritance and protein synthesis. Key concepts include d)prediction of inheritance of traits based on the Mendelian laws of heredity; h)use, limitations, and misuse of genetic information

3. Chapter 8 Genetics is the branch of biology that focuses on heredity. Cross is the mating or breeding of two individuals. The passing of traits from parents to offspring is called Heredity.

4. Chapter 8 Gregor Johann Mendel Experimented with garden peas. His knowledge of math enabled him to discover the patterns of inheritance that are the basis of genetics

5. Chapter 8 Why the Pea 1.Several traits in two different forms. 2. The mating could be controlled since the male and female reproductive parts are on the same flower. 3. The pea grows quickly enabling results to be obtained quickly.

6. Chapter 8 Monohybrid cross is a cross that involves one pair of contrasting traits. Mendel’s initial experiments were monohybrid crosses.

7. Chapter 8 Three Steps of the Experiment. 1. Grew several generations by self pollinating to obtain true-breeding (produce only one trait) for a trait. He used these plants as the parental generation, P generation.

8. Chapter 8 2. Cross-pollinated two P generation plants with contrasting forms of the trait. This generation was called the first filial generation or F1 generation. 3. He then crossed the F1 generation to obtain the second filial generation or F2 generation.

9. Chapter 8 Results 1. F1 plants showed only one form of the trait, the contrasting form disappeared. 2. The missing trait appeared in the F2 generation in the radio of 3:1.

10. Chapter 8 Mendel’s Results Ratios Flower Color 705 Purple 224 White Ratio is 705 to 224 224 224 3.15 : 1

11. Chapter 8 Objective: Learn the laws and theory of heredity, pp. 166-169. Bio 6 d, h BIO.6The student will investigate and understand common mechanisms of inheritance and protein synthesis. Key concepts include d)prediction of inheritance of traits based on the Mendelian laws of heredity; h)use, limitations, and misuse of genetic information

12. Chapter 8 Hypotheses 1. For each inherited trait, an individual has two copies of the gene—one from each parent. 2. There are alternative versions of genes The different versions of a gene are called alleles.

13. Chapter 8 3. When two different alleles occur together, one of them may be completely expressed while the other may have no observable effect on the organism’s appearance. The expressed form of the trait is the dominant trait and the trait not expressed is the recessive trait.

14. Chapter 8 4. When gametes are formed, the alleles for each gene in an individual separate independently of one another. Thus, gametes carry only one allele for each inherited trait. When gametes unite during fertilization, each gamete contributes one allele.

15. Chapter 8 Shorthand Representations Dominant Alleles—First letter of the trait capitalized. Recessive Alleles—First letter of the dominant trait, lower case.

16. Chapter 8 Flower Color Dominant—Purple Recessive—White Pp

17. Chapter 8 Homozygous is where the two alleles of a particular gene are the same. PP or pp Heterozygous is where the alleles are different. Pp

18. Chapter 8 Freckles F vs. No Freckles f Genotype is the set of alleles. FF, ff, or Ff Phenotype is the physical appearance of the trait. Freckles or no freckles

19. Chapter 8 Laws of Heredity Law of segregation — Two alleles for a trait separate when the gametes are formed. Law of independent assortment — The alleles of different genes separate independently of one another during gamete formation.

20. Chapter 8 Objective: Learn to use Punnett Squares to predict the outcome of genetic crosses, pp. 170-176. Bio 6 d, h BIO.6The student will investigate and understand common mechanisms of inheritance and protein synthesis. Key concepts include d)prediction of inheritance of traits based on the Mendelian laws of heredity; h)use, limitations, and misuse of genetic information

21. Chapter 8 Drawing the Square 1. One parent’s alleles on top and one parent’s alleles on the side. 2. Split he gametes, one allele per column on top and one allele per row on the side 3. Place capitals first, bring down the gametes at the top of the column into each box. 4. Place the gametes on the side in each box of the row.

22. Chapter 8 Test Cross is done to determine if the phenotype being observed is homozygous or heterozygous. Probability is used to predict the test cross. It is the likelihood that a specific event will occur.

23. Chapter 8 Pedigree Pedigree is a family history used to show a trait over several generations. Males ar usually boxes and females are circles.

24. Chapter 8 Traits Autosomal appear in both sexes equally. Sex-linked are usually recessive and located on the X chromosome. A male with the trait will exhibit the condition. Females will exhibit the trait only if they are homozygous recessive.

25. Chapter 8 Objective: Learn the factors that influence the patterns of heredity, pp. 177-182 Bio 6 d, h BIO.6The student will investigate and understand common mechanisms of inheritance and protein synthesis. Key concepts include d)prediction of inheritance of traits based on the Mendelian laws of heredity; h)use, limitations, and misuse of genetic information

26. Chapter 8 Incomplete Dominance Trait displayed is intermediate between the two parents. Red flowerWhite Flower P Red flower White Flower Pink Flower F 1 Pink Flower

27. Chapter 8 Multiple Alleles Several alleles determine the phenotype. Blood Type 3 Alleles I A I B i

28. Chapter 8 Codominance Two dominant alleles for the same trait are expressed at the same time. Blood Type I A I B AB blood Type

29. Chapter 8 Environment An individual’s phenotype depends on the environment. Artic Fox Summer Pigments made by enzymes. Winter the genes for pigment enzymes does not function, fox is white.

30. Chapter 8 Genetic Disorders Sickle Cell Anemia A recessive disorder that produces defective hemoglobin. Causes the blood cell to distort and at times clog up vessels. Heterozygous individuals tend to be resistant to malaria.

31. Chapter 8 Cystic Fibrosis (CF) Recessive Airways become clogged with excessive mucus. Occurs in Caucasians.

32. Chapter 8 Hemophilia Recessive Impairs the bloods ability to clot. Mutation of genes on the X chromosome causes type A. Males receiving the X chromosome with the gene will develop hemophilia.

33. Chapter 8 Huntington’s Disease (HD) Dominant allele on an autosome. Deterioration of brain tissue in middle age.

34. Chapter 8 Gene Therapy