1. Chapter 15 The Chromosomal Basis of Inheritance

2. Timeline

3. Sutton

5. Morgan

6. Fruit Fly

7. Life Cycle u Egg u Larva u Pupa u Adult

8. Reasons

9. Fruit Fly Chromosomes

10. Genetic Symbols

11. Examples u Recessive mutation: u w = white eyes u w+ = red eyes u Dominant Mutation u Cy = Curly wings u Cy+ = Normal wings

12. Morgan Observed:

13. Morgan crossed

14. The F1 offspring: u All had red eyes. u This suggests that white eyes is a genetic _________?

15. F1 X F1 = F2

16. Morgan discovered:

17. Fruit Fly Chromosomes

19. Morgan Discovered

20. Linked Genes

21. Body Color and Wing type

22. Example b+b vg+vg X bb vgvg (b+ linked to vg+) (b linked to vg) If unlinked: 1:1:1:1 ratio. If linked: ratio will be altered.

26. Crossing-Over

27. If Genes are Linked:

28. Linkage Strength

29. Genetic Maps

30. u Comment - only good for genes that are within 50 map units of each other. Why?

31. Genetic Maps

33. Sex Linkage in Biology

35. Chromosomal Basis of Sex in Humans

36. Human Chromosome Sex

39. SRY

40. Sex Linkage

41. Males

42. X-linked Disorders

43. Samples of X-linked patterns:

44. X-linked Patterns

45. Comment u Watch how questions with sex linkage are phrased: u Chance of children? u Chance of males?

46. Can Females be color-blind?

47. Y-linkage

48. Sex Limited Traits

49. Sex Influenced Traits

50. Baldness

51. Barr Body

52. Lyon Hypothesis

53. Examples

54. Calico Cats u X B = black fur u X O = orange fur u Calico is heterozygous, X B X O.

56. Question? u Why don’t you find many calico males?

57. Chromosomal Alterations

58. Number Alterations

59. Aneuploidy

61. Comment

62. Types of Aneuoploidy

63. Turner Syndrome

64. Characteristics

65. Question u Why are Turner Individuals usually sterile

66. Other Sex Chromosome changes

67. Kleinfelter Syndrome

69. George Washington u May have been a Kleinfelter Syndrome individual. u Much taller than average. u Produced no children.

70. Meta female

71. Super male

73. Trisomy events

75. Question? u Why is trisomy more common than monosomy?

76. Question? u Why is trisomy 21 more common in older mothers?

77. Polyploid

78. Question? u In plants, even # polyploids are often fertile, why odd # polyploids are sterile. Why?

79. Structure Alterations

80. Result

82. Translocations

83. Cri Du Chat Syndrome

84. Philadelphia Chromosome

85. Parental Imprinting of Genes

86. Example:

87. Cause:

91. Result

92. Why have parental imprinting? u Method to detect that TWO different sets of chromosomes are in the zygote.

93. Experiment u Can fuse nuclei into mouse eggs. u If male/male = normal placenta, abnormal fetus u If female/female = abnormal placenta, normal fetus u If male/female = normal placenta and normal fetus

94. Extranuclear Inheritance

95. Result

96. Mitochondria

97. Chloroplasts

98. Variegated Examples

99. Variegation in African Violets

100. Comment u Cells can have a mixture of normal and abnormal organelles. u Result - degree of expression of the maternal inherited trait can vary widely.

101. Summary u Know about linkage and crossing-over. u Sex chromosomes and their pattern of inheritance. u Variations of chromosomes and inheritance patterns.

102. Summary u Be able to work genetics problems for this chapter.