Honors Biology Ch. 11

1. Honors BiologyCh. 11 Complex Inheritance and Human Heredity

2. I. Human Inheritance • - heredity in humans is the same as in other organisms • - most genetic diseases are recessive and rare

3. A. Recessive Traits • - diseases caused by a single defective gene/protein • 1. Cystic Fibrosis (CF) • 2. Tay-Sachs Disease • 3. Albinism • 4. Phenylketonuria (PKU) • 5. Sickle-Cell Anemia

5. Woody Guthrie B. Dominant Traits • 1. Huntington’s Disease - rare, degenerative nervous system disorder

6. 2. Achondroplasia • - a disorder of bone growth • - homozygous dominant condition is fatal

7. 3. Polydactyly

8. II. Other Inheritance Patterns • A. Sex Chromosomes: • - pair of chromosomes that determine an individual’s sex • XX - female XY - male • Autosomes:the other chromosome pairs except the sex chromosomes

9. Human Chromosomes:44 Autosomes

10. Human Chromosomes:2 Sex Chromosomes

11. B. Sex-Linked Traits: • - trait controlled by a recessive allele on the "X" sex chromosome • - more common in males • - Ex. Red-green color-blindness, hemophilia

12. Can you see a number?

13. Queen Victoria’s Family

14. Pedigree of Europe’s Royal Families

15. C. Sex-Influenced Traits: • - trait controlled by an allele that is recessive in females and dominant in males • - Ex. Male-pattern Baldness

16. D. Incomplete Dominance: • - a trait in which the heterozygote shows a blending of traits • - Ex. Carnations and Snap dragons: • R - red, W - white, RW - pink

17. Incomplete Dominance: P R R Homozygous Red Parent W R W R W Homozygous White Parent Pink Pink W R W R W Pink Pink

18. Incomplete Dominance: F1 R W HeterozygousPink Parent R R R R W Heterozygous Pink Parent Red Pink R W W W W Pink White

19. E. Codominance: • - a trait in which the heterozygote shows both alleles equally • - Ex. Horses: • R - red, W - white, RW - roan • - Ex. ABO Blood Groups • A B AB

20. E. Codominance: Roan Horses

21. E. Codominance: ABO Blood Groups

22. F. Polygenic Inheritance: • - traits controlled by more than one pair of genes • - Ex. hair, skin, and eye color

23. dark brown light brown light brown blue AAbB AAbb AabB Aabb dark brown light brown light brown blue aABB aABb aaBB aaBb light brown blue blue light blue aABb aABb aaBb aabb EGGS Mother AB Ab aB ab AaBb black dark brown dark brown light brown Human Eye Color AB AABB AABb AaBB AaBb Ab Father SPERM AaBb aB ab

24. Human Skin Color

25. G. Epistasis - A gene at one locus alters the phenotypic expression of a gene at a second locus. - Example: black, brown, and white coat in mice

26. BbCc BbCc  Sperm 1⁄4 bC 1⁄4 Bc 1⁄4 BC bc 1⁄4 Eggs 1⁄4 BBCC BbCC BbCc BC BBCc 1⁄4 bC BbCC bbCC bbCc BbCc 1⁄4 BBcc BBCc BbCc Bbcc Bc bbcc Bbcc BbCc 1⁄4 bbCc bc 4⁄16 9⁄16 3⁄16 Epistasis: Black, Brown, and White Coat in Mice

27. H. Multiple Alleles: • 1. ABO Blood Groups: • - 4 blood types: A, B, AB, O • - caused by a protein in the membranes of red blood cells • - 3 alleles for this protein: IA, IB, i

28. - Genotypes for the 4 blood types: • Type A: IA IA, IAi • Type B: IB IB, IBi • Type AB: IA IBUniversal Recipient • Type O: ii Universal Donor

29. 2. Rh Blood Groups: • - an example of multiple alleles • - there are about 8 dominant alleles (+) • - one recessive allele (-)

30. III. Nondisjunction: • - homologous chromosomes fail to separate during meiosis

31. III. Nondisjunction: • - Down Syndrome (Trisomy 21) • - Klinefelter’s Syndrome (XXY) • - XYY Syndrome • - Turner’s Syndrome (Monosomy X) (X) • - Trisomy X (XXX)

32. Down syndrome(Trisomy 21)

33. 400 300 Number per 1000 Births 200 100 0 10 20 30 40 50 Age of Mother (years) Incidence of Down Syndrome

34. Turner’s Syndrome (Monosomy X)

35. XYY Syndrome

36. Trisomy X (XXX)

37. Klinefelter’s Syndrome (XXY)

38. Down Syndrome (Trisomy 21)

39. Normal Female

40. Edward’s Syndrome (Trisomy 18)

41. IV.Fetal Testing: • - Amniocentesis • - Chorionic Villus Sampling • - Ultrasound

42. Amniocentesis

43. Head Body Head Body Ultrasound image

44. Ultrasound Of Fetus

45. The End

46. Human Chromosomes(23 homologous pairs)