The document summarizes key concepts in genetics discovered by Gregor Mendel through his experiments with pea plants, including: - Mendel performed breeding experiments with pea plants and discovered the laws of segregation and independent assortment. - He found that traits are passed from parents to offspring through discrete factors (now known as genes and alleles) that sort independently during gamete formation and fertilization. - Mendel's work laid the foundation for modern genetics concepts such as genotypes, phenotypes, dominance, and the use of Punnett squares to predict offspring ratios. - The document also discusses how Mendel's principles can be applied to understand human genetic disorders and inheritance patterns such as autosomal and

1. Copyright © The McGraw-Hill Companies, Inc. Permission required for reproduction or display. Parents eggs Ee Ee spem Punnett square Offspring E e E e Ee Ee EE ee TT tt t T Tt eggs sperm Offspring T t T t TT Tt Tt tt

4. Gregor Mendel Copyright © The McGraw-Hill Companies, Inc. Permission required for reproduction or display. © Ned M. Seidler/Nationa1 Geographic Image Collection

5. Fruit and Flower of the Garden Pea Copyright © The McGraw-Hill Companies, Inc. Permission required for reproduction or display. a. Flower Structure filament anther stamen stigma style ovules in ovary carpel

6. Garden Pea Traits Studied by Mendel Copyright © The McGraw-Hill Companies, Inc. Permission required for reproduction or display. Cutting away anthers Brushing on pollen from another plant All peas are yellow when one parent produces yellow seeds and the other parent produces green seeds.

9. Mendel’s Monohybrid Crosses: An Example Copyright © The McGraw-Hill Companies, Inc. Permission required for reproduction or display. TT tt t T P generation P gametes F 1 gametes F 2 generation F 1 generation Tt T t sperm T t TT Tt Tt tt Offspring Phenotypic Ratio short 1 tall 3 Allele Key T = tall plant t = short plant

12. Homologous Chromosomes Replication alleles at a gene locus sister chromatids b. Sister chromatids of duplicated chromosomes have same alleles for each gene. a. Homologous chromosomes have alleles for same genes at specific loci. G R S t G R S t G R S t g r s T g r s T g r s T Copyright © The McGraw-Hill Companies, Inc. Permission required for reproduction or display.

14. Genotype versus Phenotype

17. Punnett Square Showing Earlobe Inheritance Patterns Copyright © The McGraw-Hill Companies, Inc. Permission required for reproduction or display. Parents Ee Ee eggs spem Punnett square Offspring E e E e Ee Ee EE e e Allele key Phenotypic Ratio unattached earlobes 3 1 E = unattached earlobes e = attached earlobes attached earlobes

19. One-Trait Test Cross Insert figure 11.7a here Phenotypic Ratio eggs a. sperm t T t Offspring Tt tt Tt tt Allele Key short 1 tall 1 T = tall plant t = short plant Copyright © The McGraw-Hill Companies, Inc. Permission required for reproduction or display.

20. One-Trait Test Cross Copyright © The McGraw-Hill Companies, Inc. Permission required for reproduction or display. b. t T Tt Offspring eggs sperm TT tt Allele Key Phenotypic Ratio All tall plants T = tall plant t = short plant

22. Two-Trait (Dihybrid) Cross Copyright © The McGraw-Hill Companies, Inc. Permission required for reproduction or display. TtGg ttgg TTGG Offspring P generation P gametes F 2 generation F 1 generation F 1 gametes eggs sperm TG Tg TG Tg tg tG tG tg tg TG TTGg TtGG TtGg TTGg Ttgg TtGG ttGG ttGg TtGg Ttgg ttGg ttgg TTGG TtGg TTgg TtGg Allele Key = = = = T t G g tall plant short plant green pod yellow pod Phenotypic Ratio 9 tall plant, green pod 3 tall plant, yellow pod 3 short plant, green pod 1 short plant, yellow pod

23. Independent Assortment and Segregation during Meiosis Copyright © The McGraw-Hill Companies, Inc. Permission required for reproduction or display. Parent cell has two pairs of homologous chromosomes. All possible combina- tions of chromosomes and alleles occur in the gametes as suggested by Mendel's two laws. All orientations of ho- mologous chromosomes are possible at meta- phase I in keeping with the law of independent assortment. At metaphase II, each daughter cell has only one member of each homologous pair in keeping with the law of segregation. A A A A A A A AB ab Ab aB a a a a a a a A A b A a a a B B B B B B B B B B a B b b b A A b b B B a a b b b b b A b b either or

24. Animation Please note that due to differing operating systems, some animations will not appear until the presentation is viewed in Presentation Mode (Slide Show view). You may see blank slides in the “Normal” or “Slide Sorter” views. All animations will appear after viewing in Presentation Mode and playing each animation. Most animations will require the latest version of the Flash Player, which is available at http://get.adobe.com/flashplayer.

29. Cystic Fibrosis Copyright © The McGraw-Hill Companies, Inc. Permission required for reproduction or display. Cl - H 2 O H 2 O H 2 O Cl - Cl - Cl - Cl - thick mucus defective channel nebulizer percussion vest © Pat Pendarvis

30. Methemoglobinemia Copyright © The McGraw-Hill Companies, Inc. Permission required for reproduction or display. Courtesy Division of Medical Toxicology, University of Virginia

31. Animation Please note that due to differing operating systems, some animations will not appear until the presentation is viewed in Presentation Mode (Slide Show view). You may see blank slides in the “Normal” or “Slide Sorter” views. All animations will appear after viewing in Presentation Mode and playing each animation. Most animations will require the latest version of the Flash Player, which is available at http://get.adobe.com/flashplayer.

33. A Victim of Huntington Disease Copyright © The McGraw-Hill Companies, Inc. Permission required for reproduction or display. a: © Steve Uzzell JJ JK JK JK JK JJ K L JK JK JK JK K L JK JK K L KK K L J L JJ J L JK J L K L KL J L J L J L J L JJ K L JJ K L JJ K L K L a. b.

35. Incomplete Dominance Copyright © The McGraw-Hill Companies, Inc. Permission required for reproduction or display. R 1 R 2 R 1 R 2 R 1 R 2 R 1 R 2 R 1 R 1 R 2 R 2 R 1 R 2 R 1 R 2 eggs sperm Offspring Key 1 R 1 R 1 2 R 1 R 2 1 R 2 R 2 red pink white

37. Multiple Allelic Traits

39. Marfan Syndrome Copyright © The McGraw-Hill Companies, Inc. Permission required for reproduction or display. (Left): © AP/Wide World Photos; (Right): © Ed Reschke Chest wall deformities Long, thin fingers, arms, legs Scoliosis (curvature of the spine) Flat feet Long, narrow face Loose joints Skeleton Skin Lungs Eyes Mitral valve prolapse Lens dislocation Severe nearsightedness Collapsed lungs Stretch marks in skin Recurrent hernias Dural ectasia: stretching of the membrane that holds spinal fluid Enlargement of aorta Heart and blood vessels Aneurysm Aortic wall tear Connective tissue defects

41. Frequency Distributions in Polygenic Inheritance Copyright © The McGraw-Hill Companies, Inc. Permission required for reproduction or display. F 2 generation F 1 generation P generation aabbcc Aabbcc AaBbcc AaBbCc AABbCc AABBCc AABBCC Genotype Examples 1 64 — 6 — 64 15 — 64 20 — 64 Proportion of Population

43. X – Linked Inheritance Copyright © The McGraw-Hill Companies, Inc. Permission required for reproduction or display. Offspring eggs sperm P generation P gametes F 2 generation F 1 generation F 1 gametes X R X R X r Y X r X R Y X R Y X R X r X r X R X R X r X R X R X r Y X R Y X R Y Allele Key X R = red eyes X r = white eyes Phenotypic Ratio females: all red-eyed males : 1 red-eyed 1 white-eyed

45. X-Linked Recessive Pedigree Copyright © The McGraw-Hill Companies, Inc. Permission required for reproduction or display. X B X B X b Y grandfather daughter X B X b X B Y X B Y X b X b X b Y X B X b grandson X B Y X B X B X b Y Key X B X B = Unaffected female X B X b = Carrier female X b X b = Color-blind female X b Y = Unaffected male X b Y = Color-blind male X-Linked Recessive Disorders • More males than females are affected. • An affected son can have parents who have the normal phenotype. • For a female to have the characteristic, her father must also have it. Her mother must have it or be a carrier. • The characteristic often skips a generation from the grandfather to the grandson. • If a woman has the characteristic, all of her sons will have it.

46. Muscle Dystrophy Copyright © The McGraw-Hill Companies, Inc. Permission required for reproduction or display. (Abnormal): Courtesy Dr. Rabi Tawil, Director, Neuromuscular Pathology Laboratory, University of Rochester Medical Center; (Boy): Courtesy Muscular Dystrophy Association; (Normal): Courtesy Dr. Rabi Tawil, Director, Neuromuscular Pathology Laboratory, University of Rochester Medical Center. abnormal muscle normal tissue fibrous tissue

49. Copyright © The McGraw-Hill Companies, Inc. Permission required for reproduction or display. Parents eggs Ee Ee spem Punnett square Offspring E e E e Ee Ee EE ee TT tt t T Tt eggs sperm Offspring T t T t TT Tt Tt tt