1. Chapter 14 Mendel and the Gene Idea

2. Inheritance

3. Genetics

4. Genetic Theories 1

5. Genetic Theories (cont.)

6. Gregor Mendel

7. u Mendel’s paper published in 1866, but was not recognized by Science until the early 1900’s.

8. Reasons for Mendel's Success

9. u Mendel was a pea picker. u He used peas as his study organism.

10. Why Use Peas?

11. Cross-pollination

13. Self-pollination

14. Mendel's Work

15. Monohybrid or Mendelian Crosses

16. P Generation

17. Offspring

21. Another Sample Cross P1 Tall X short (TT x tt) F1 all Tall (Tt) F2 3 tall to 1 short (1 TT: 2 Tt: 1 tt)

22. Results - Summary

23. Mendel's Hypothesis

25. 4

26. Law of Segregation

27. Mendel’s Experiments

28. Vocabulary

30. Helpful Vocabulary

31. 6 Mendelian Crosses are Possible Cross Genotype Phenotype TT X tt all Tt all Dom Tt X Tt 1TT:2Tt:1tt 3 Dom: 1 Res TT X TT all TT all Dom tt X tt all tt all Res TT X Tt 1TT:1Tt all Dom Tt X tt 1Tt:1tt 1 Dom: 1 Res

32. Test Cross

34. Dihybrid Cross

35. Number of Kinds of Gametes

36. Equation The formula 2 n can be used, where “n” = the number of heterozygous traits. Ex: TtRr, n=2 2 2 or 4 different kinds of gametes are possible. TR, tR, Tr, tr

37. Dihybrid Cross

38. Results u 9 Tall, Red flowered u 3 Tall, white flowered u 3 short, Red flowered u 1 short, white flowered Or: 9:3:3:1

39. Law of Independent Assortment

41. Comment

42. Probability

44. Genetic Ratios

45. Rule of Multiplication

46. Example: TtRr X TtRr

47. Comment

48. Variations on Mendel

49. Incomplete Dominance

51. Result

52. Another example

53. Codominance

54. Result

55. Multiple Alleles

56. Result

57. Alleles and Blood Types Type Genotypes A I A I A or I A i B I B I B or I B i AB I A I B O ii

60. Comment

61. Epistasis

62. Gerbils

63. In Gerbils CcBb X CcBb Brown X Brown F1 = 9 brown (C_B_) 3 black (C_bb) 4 albino (cc__)

64. Result

65. Epistasis in Mice

66. Problem u Wife is type A u Husband is type AB u Child is type O Question - Is this possible? Comment - Wife’s boss is type O

67. Bombay Effect

68. Genotypes

69. Bombay - Detection

70. Polygenic Inheritance

71. Genetic Basis

73. Result

74. Genetic Studies in Humans

75. Pedigree Chart Symbols Male Female Person with trait

76. Sample Pedigree

77. Dominant Trait Recessive Trait

78. Human Recessive Disorders

79. Sickle-cell Disease

81. Tay-Sachs

82. Cystic Fibrosis

83. Recessive Pattern

84. Human Dominant Disorders

85. Inheritance Pattern

86. Genetic Screening

87. General Formal R = F X M X D R = risk F = probability that the female carries the gene. M = probability that the male carries the gene. D = Disease risk under best conditions.

88. Example

89. Risk Calculation u Wife = probability is 1.0 that she has the allele. u Husband = with no family record, probability is near 0. u Disease = this is a recessive trait, so risk is Aa X Aa =.25 u R = 1 X 0 X.25 u R = 0

90. Risk Calculation u Assume husband is a carrier, then the risk is: R = 1 X 1 X.25 R =.25 There is a.25 chance that any child will be albino.

91. Common Mistake

92. Carrier Recognition

93. Fetal Testing

94. Amniocentesis

96. Chorionic Villi Sampling

99. Newborn Screening

101. Multifactorial Diseases

102. Ex. Heart Disease

103. Summary u Know the Mendelian crosses and their patterns. u Be able to work simple genetic problems (practice). u Watch genetic vocabulary. u Be able to read pedigree charts.

104. Summary u Be able to recognize and work with some of the “common” human trait examples.