1. Chapter 12 Patterns of Inheritance

2. 2 Chapter 12Genetics Field founded by Gregor Mendel Worked with sweet pea Knew nothing of cells, chromosomes, etc.; also interested in math. Was unappreciated by peers Work was rediscovered after Darwin

3. 3 Chapter 12Mendel

4. 4 Seeds & Flowers of Edible Pea Intact pea flower Flower dissected to show reproductive structures Stamens (male) produce pollen Carpel (female) produces eggs

5. 5 Chapter 12 Definitions 1 Must know these!!! Trait—A variable characteristic of organism Gene—A segment of chromosomal DNA controlling a specific trait Locus—Chromosomal position where DNA for a specific gene lives Genome—Refers to all standard loci for a species

6. 6 Chapter 12 Definitions 2 Must know these!!! Alleles—Different forms of a gene “Flower color” is a gene; “Flower color” is a gene; “Purple” is one flower-color allele “Purple” is one flower-color allele “White” is another flower-color allele “White” is another flower-color allele Genotype—List of alleles for an individual at specific genes Familiar organisms are diploid Familiar organisms are diploid One or two alleles per individual One or two alleles per individual

7. 7 Chapter 12 Definitions 3 Homozygous—Maternal & paternal alleles same Father donates purple-flower allele Father donates purple-flower allele Mother donates purple-flower allele Mother donates purple-flower allele Heterozygous—Maternal & paternal alleles differ Father donates purple-flower allele Father donates purple-flower allele Mom donates white-flower allele Mom donates white-flower allele

8. 8 Chapter 12 Definitions 4 Phenotype: List of traits exhibited by individual List of traits exhibited by individual Doesn’t always represent genotype Doesn’t always represent genotype Dominant—Allele that is expressed 100% in heterozygote Recessive—Allele is not expressed in heterozygote Incomplete dominance—heterozygote displays intermediate trait

9. 9 Chapter 12 1234567891011121314151617181920212223242526Loci: Genes, Alleles, Loci, and Chromosomes Chromosome from One Parent Homologous Chromosome from Other Parent 1234567891011121314151617181920212223242526Loci: M locus has gene that controls leaf color. Plant homozygou s for this gene D locus has gene that controls plant height. Plant homozygou s for this gene Bk locus has gene that controls fruit shape. Plant heterozygou s for this gene

10. 10 Chapter 12 Genetic Symbolism Often use initial letter of dominant allele Capital letter represents dominant Capital letter represents dominant Lower case of same letter represents recessive Lower case of same letter represents recessive If purple flower dominant to white… “P” represents allele for purple “P” represents allele for purple “p” represents allele for white “p” represents allele for white

11. 11 Chapter 12 Foundation Genetics Mendel’s Laws 1. Law of Dominance a.Interaction of the two resulting in expression of only one Aa Dominant Recessive

12. 12 Chapter 12 II. The foundation of genetics A - a A a 2. Law of Segregation a. Paired alleles of a gene separate during meiosis resulting in a gamete that contains only a single allele for each gene present

13. 13 Chapter 12 II. The foundation of genetics 3. Law of Independent Assortment Pairs of alleles (genes) that control different traits segregate independently of each other during meiosis (genes) if the alleles are on separate chromosomes

14. 14 Chapter 12 Independent Assortment 1a - 1b 2a - 2b 3a - 3b 1a 1b 2b 3a 2a 3b

15. 15 Chapter 12 Linear order - Linkage Red Allele, p Round Allele, l Purple Allele, P Long Allele, L Flower color gene Pollen shape gene

16. 16 Chapter 12 Cross Fertilization of Parents True-breeding Purple-flowered Parent True- breeding White- flowered Parent Cross-Fertilize All Purple-flowered Offspring Pollen P P F1F1

17. 17 Chapter 12 Self-fertilization of F 2 F1F1 Self-Fertilize F2F2 F2F2 F2F2 F2F2 75% Purple 25% White

18. 18 Chapter 12 Genotype vs Phenotype Phenotype is how we look/behave Purple flowers Purple flowers White flowers White flowers Genotype is what our genes say White Flowers / White Flowers White Flowers / White Flowers White Flowers / Purple Flowers White Flowers / Purple Flowers Purple Flowers / Purple Flowers Purple Flowers / Purple Flowers

19. 19 Chapter 12 Genotype vs Phenotype 2 Genotypes PP = homozygous for purple flower PP = homozygous for purple flower pp = homozygous for white flower pp = homozygous for white flower Pp = heterozygous for flower color Pp = heterozygous for flower color Phenotype from genotype: PP = purple flower PP = purple flower Pp = purple flower Pp = purple flower pP = purple flower pP = purple flower pp = White flower pp = White flower

20. 20 Chapter 12 Genotype - Phenotype

21. 21 Chapter 12 Gametes of Homozygotes AA AA Homozygous ParentGametes All gametes identical regarding this gene

22. 22 Chapter 12 Gametes of Heterozygotes Aa Aa Heterozygous ParentGametes Gametes 50/50 regarding this gene

23. 23 Chapter 12 pp homozygou s recessive Homozygous Dominant X Homozygous Recessive P p Pp Purple Parent PP homozygou s dominant White Parent sperm nuclei egg nuclei sperm nuclei egg nuclei

24. 24 Chapter 12 Pp pP P Sperm + p Eggs same as p Sperm + P Eggs Purple F 1 P p sperm nucleus egg nucleus + p P egg nucleus sperm nucleus +

25. 25 Chapter 12 Purple homozygous dominant (PP) Purple heterozygous (Pp) Purple heterozygous (pP) White homozygous recessive (pp) Pp X Pp Cross P p p Pp P P p + + + + F 1 Sperm F 1 Eggs F 2 Offspring

26. 26 Chapter 12 Using Punnett Squares in Genetic Crosses Named after geneticist Reginald Punnett Figured using Punnett squares Considers only genes of interest Considers only genes of interest List sperm genotypes across top List sperm genotypes across top List egg genotypes down side List egg genotypes down side Fill in boxes with zygote genotypes Fill in boxes with zygote genotypes

27. 27 Chapter 12 Pp 1(25%) White 3 (75%) Purple Frequencies Phenotypes Genotypes Frequencies Making a Punnett Square: Heterozygous X Heterozygous Eggs of Heterozygous Plant Pollen of Heterozygous Plant 11 2 P p pP PpPP pp PPpppPPp

28. 28 Chapter 12Probability

29. 29 Chapter 12ProbabilityProbability Coin Toss Probability of heads = 1/2 or 50% Probability of tails = 1/2 or 50% 10 tosses - 7th toss = heads 10 tosses - 4th toss = heads 10 tosses - 3rd toss = tails 1/2 1/2 1/2 3 tosses in a row = heads 1/8 1/2 (1st toss) X 1/2 (2nd toss) X 1/2 (3rd toss)

30. 30 Chapter 12 Consider Flower Color Pretend flower color affected by only one gene (monohybrid cross) Assume all alleles are purple or white Purple (P) is dominant to white (p) Heterozygotes will have flowers as purple as homozygous dominants

31. 31 Chapter 12 pp (50%) White (50%) Purple Frequencies Phenotypes Genotypes Frequencies Test Cross: Heterozygous X Homozygous Recessive Eggs of Homozygous Recessive Pollen of unknown plant with dominant phenotype (Heterozygous) 2 P p pp PpPp pp pppPpp 2

32. 32 Chapter 12 pp (100%) Purple Frequencies Phenotypes Genotypes Frequencies Test Cross: Homozygous X Homozygous Recessive Eggs of Homozygous Recessive Pollen of unknown plant with dominant phenotype (Homozygous) P Pp PpPp Pp PpPpPpPp P 4

33. 33 Chapter 12 Traits of Peas Studied by Mendel Plant size Flower location Flower color Pod color Pod shape Seed shape Seed color

34. 34 Chapter 12 Dihybrid Cross: S s Y y X S s Y y SY SySySySy sYsYsYsY sy SsYy Parent Self-fertilizes 1414 1414 1414 1414 SY SySySySy sYsYsYsYsy 1414 1414 1414 1414 Eggs Sperm 1 16 SSYY SSY y S s YY SsYySsYySsYySsYy SS y Y SS yy S sy Y S syy s SYY s SY y ss YY ss Y y sSyYsSyYsSyYsSyY s S yy ssy Y ssyy

35. 35 Chapter 12 Dihybrid Cross - Probability B = Brown Eyes b = Blue Eyes A = Black Hair a = Blond Hair P Generation BbAa BbAa Possible Gametes Male Female male BA,Ba,bA,b a Female

36. 36 Chapter 12 Dihybrid Probability AB Ab aB ab AB Ab aB ab ABA B AABb AaB B AaBb AABb AAbb AaBb Aabb AaBB AaBbaaBB aaBb AaBbAabb aaBb aabb Black Hair - Brown eyes Black Hair - Blue Eyes 9 3 Blond Hair - Brown Eyes Blond Hair - Blue Eyes 3 1

37. 37 Chapter 12 Dihybrid Probability - Math Solved Brown Eyes = B Brown Eyes = B Blue Eyes = b Black Hair = A Blond Hair = a Male BbAa Female BbAa Probability = 3/4 Probability = 1/4 Probability = 3/4 Probability = 1/4

38. 38 Chapter 12 Dihybrid Probability - Math Solved 3/4 B- 1/4 bb 3/4 A - 1/4 aa X 9/16 B-A- 3/16 bbA- 3/16 B-aa 1/16 bbaa

39. 39 Chapter 12Linkage Red Allele, p Round Allele, l Purple Allele, P Long Allele, L Flower color gene Pollen shape gene

40. 40 Chapter 12 Incomplete Dominance

41. 41 Chapter 12 Incomplete Dominance

42. 42 Chapter 12 RR (100%) Pink (intermediate) Frequencies Phenotypes Genotypes Frequencies Incomplete Dominance: Homozygous-X Homo Recessive Eggs of Homozygous Red Parent Eggs of Homozygous RR Red Parent Pollen of Homozygous White Parent Pollen of Homozygous R ' R ' White Parent R' R R R R R'R Pink 1

43. 43 Chapter 12 (25%)(25%) Red White RR' (50%) Pink Frequencies Phenotypes Genotypes Frequencies Incomplete Dominance: F 1 X F 1 Eggs of Heterozygous Pink F 1 Parent Eggs of Heterozygous RR ' Pink F 1 Parent Pollen of Heterozygous Pink F 1 Parent Pollen of Heterozygous RR ' Pink F 1 Parent R R' R' R R RR RRR'R'RR'R'R11 2 RedPink White

44. 44 Chapter 12 Normal Red Blood Cells - Pleiotropy

45. 45 Chapter 12 Sickled Cells - Pleiotropy

46. 46 Chapter 12Pleiotropy

47. 47 Chapter 12 Epistasis two sets of genes working together

48. 48 Chapter 12 Polygenic Inhertance - multiple genes Three Sets of Genes Working in tandem AABBCC AaBbCc aabbcc Skin Color Height Eye Color

49. 49 Chapter 12 Polygenic Inhertance - multiple genes

50. 50 Chapter 12 AB Ab aB ab ABAbaBab Huma n Eye Color EGGS SPERM Mother AaBb Father AaBb AABBAABbAaBBAaBb blackdark browndark brownlight brown AAbB dark brown AAbb light brown AabB Aabbblue aABBaABbaaBBaaBb dark brown light brown blue aABbaAbbaaBbaabb blueblue light blue

51. 51 Chapter 12 Multiple Alleles Blood Type A - B - AB - O A AA - Ao B BB - Bo AB AB O oo Genotype

52. 52 Chapter 12 10% 34% 37% 4% B or AB A or AB O,AB, A,B (universal) AB B or O A or O O AB, A, B, O (universal) A B A & B Neither BB or BO AA or AO OO AB O AB B A FreqDonates Re- ceives Anti- bodies RBCsGenotypeType Human ABO Blood Group

53. 53 Chapter 12 RH Blood Factor RH - another Blood Protein Rh + you have the protein Rh -- you donot have the protein 85% of the population are Rh + 15% of the population are Rh − 4% of the population are AB What % of the population are AB −

54. 54 Chapter 12 Rh Blood Factor Female Rh + Male Rh − Child Rh + Female Rh − Male Rh  Child Rh  Mother will start to build up anti Rh antibodies anti Rh antibodies

55. 55 Chapter 12 X1X1X1X1 X2X2X2X2 Sex Determination in Mammals EGGS Male Parent Y XmXmXmXm SPERMSPERMSPERMSPERM Female Offspring Male Offspring Y XmXmXmXm XmXmXmXm X1X1X1X1 X2X2X2X2 XmXmXmXm YY X1X1X1X1 X2X2X2X2 X1X1X1X1 X2X2X2X2 Female Parent

56. 56 Chapter 12 Sex Determination in Mammals

57. 57 Chapter 12 Sex Linked The gene is found on the X chromosome Color Blindness - recessive trait Female possible genotypes CC Cc cc Male possible genotypes Cycy

58. 58 Chapter 12 Color Blindness

59. 59 Chapter 12 Sex Linked Genotypes Cc - Cy C c C y Cc Cc Cy cycycycy 25% colorblind 50% of the males colorblind

60. 60 Chapter 12 Sex Influenced Dominant in one sex Recessive in the other Reason: The presence or absence Testosterone Estrogen of the sex hormones

61. 61 Chapter 12 Sex Influenced Male Pattern Baldness

62. 62 Chapter 12 Sex Influenced Male Pattern Baldness Dominant in Males Recessive in Females BBBbbb Bald Bal d Nonbald Bald Nonbald Nonbald

63. 63 Chapter 12 Sex Limited Trait Trait is limited to one sex All secondary sex characteristics are sex limited

64. 64 Chapter 12 Sex Limited Trait Cabbage Butterfly Yellow white

65. 65 Chapter 12 Sex Limited Trait

66. 66 Chapter 12 Sex Limited Trait

67. 67 Chapter 12 Sex Limited Trait

68. 68 Chapter 12 How to Read Pedigrees = male= female = parents or = individual who shows the trait or = heterozygous carrier of autosomal trait = offspring 123 I, II, III, IV, or V = generation

69. 69 Chapter 12 A Recessive Pedigree

70. 70 Chapter 12 Pedigrees: Legacy of Queen Victoria

71. 71 Chapter 12 Incidence of Down Syndrome 1020304050 0 100 200 300400Age of Mother (years) N u m b e r p e r 1 0 0 0 B i r t h s

72. Chapter 12 The end

73. 73 Chapter 12 Meiosis IIMeiosis I YSSY yssy yS S y YsY s SyyS YY ss Independent Assortment SsYy S s Y y Y y S s YY S s yy S s Randomly one or the other SYYSsyys Chromosome Replication

74. 74 Chapter 12 red Purple round Long P P p p LLl l P p p LLl l PLp L l lPp PLp L l lPp LL l lPP p p P P p p L L l l P p p L L l l Crossing Over Sister Chromatids Duplicated Chromosome LL l lPP p p Sister Chromatids Homologous Chromosomes P P p p LLl l P p p LLl l pL Pl LP lp old combination new combination old combination Flower Color Pollen Shape

75. 75 Chapter 12 25% Normal f Carrier f Normal m 25%25% 25% White-e m Frequencies Phenotypes Genotypes Frequencies Sex Linkage: Eye Color in Fruit Flies Eggs of Female Eggs of X R X r Female Sperm of X R Y Male 11 Y XRXR XRXR XrXr XRXR XRXR Y XrXr XRXRXRXR XrYXrYXRXrXRXr XRYXRY R r R Female Male 11