1. Gregor Mendel “Father of Genetics” Wrote “Experiments in Plant Hybridization” in 1865 His work wasn’t discovered until the next century

2. Figure 14.0 Painting of Mendel

3. Mendel was WAY ahead of his time and one of the most important people in the history of biology !

4. Figure 14.0x Mendel

5. Table 14.1 The Results of Mendel’s F 1 Crosses for Seven Characters in Pea Plants

6. Figure 14.2 Mendel tracked heritable characters for three generations

7. Figure 14.x1 Sweet pea flowers

8. Figure 14.3 Alleles, alternative versions of a gene

9. Homozygous means having only one form of gene or allele Ex: WW or ww

10. Heterozygous means a trait represented by at least two different alleles, or forms of a gene Ex: Ww

11. Figure 14.4 Mendel’s law of segregation (Layer 2)

12. In the formation of a zygote, or fertilized egg, each parent of an organism contributes one form of a gene or allele, for each trait in most cases.

13. In Mendelian Genetics, dominant traits are represented by capital letters; recessive ones by lower case letters

14. Dominant traits (genes) are always expressed if the gene is present; recessive traits are expressed only if the dominant genes are absent

15. For example, widow’s peak (W) is a dominant trait in humans. If the gene for widow’s peak is present, W, the person will have widow’s Peak. (WW, Ww)

16. Homologous Chromosomes eye color locus b = blue eyes eye color locus B = brown eyes Paternal Maternal This person would have brown eyes (Bb)

17. Meiosis - eye color Bb diploid (2n) B b meiosis I B B b b sperm haploid (n) meiosis II

18. The physical appearance of an organism is known as the phenotype; the genetic makeup (the letters) are known as the genotype Ex: Widow’s peak is the pheno- type; Ww is the genotype

19. Figure 14.5 Genotype versus phenotype

20. The way to show the pos- sible pairings of genes between two organisms is called a Punnett Square.

21. Punnett Square Punnett square combinations gametesA Punnett square is used to show the possible combinations of gametes.

22. P generation Breed the P generation tall (TT) vs. dwarf (tt) pea plantstall (TT) vs. dwarf (tt) pea plants t t TT

23. tall (TT) vs. dwarf (tt) pea plants t t TT Tt All Tt = tall (heterozygous tall) produces the F 1 generation

24. F1 generation Breed the F1 generation Heterozygous Tall (Tt) pea plantsHeterozygous Tall (Tt) pea plants T t T t

25. Cross a purebred black guinea pig and a purebred brown guinea pig. Black is dominant over brown.

26. B b b Bb (black) (Brown) All offspring are black and heterozy gous.

27. If bushy eyebrows (B) are dominant over fine eyebrows, (b), show the cross between one parent heterozygous for the trait and one who is homozygous recessive.

28. What are the phenotypes and genotypes of the offspring? Answer: Bushy (Bb) 50% and fine (bb) 50%

29. Monohybrid Cross single trait.A breeding experiment that tracks the inheritance of a single trait. Mendel’s “principle of segregation”Mendel’s “principle of segregation” gamete (meiosis). a.pairs of genes separate during gamete formation (meiosis). gametes b.the fusion of gametes at fertilization pairs genes once again.

30. Dihybrid Cross two traits.A breeding experiment that tracks the inheritance of two traits. Mendel’s “principle of independent assortment”Mendel’s “principle of independent assortment” (metaphase I) a.each pair of alleles segregates independently during gamete formation (metaphase I) 2 n (n = # of heterozygotes) b.formula: 2 n (n = # of heterozygotes)

31. Independent Assortment Question:Question: How many different gametes can be produced for the following allele arrangements? 2 n (n = # of heterozygotes)Remember: 2 n (n = # of heterozygotes) 1.RrYy 2.AaBbCCDd 3.MmNnOoPPQQRrssTtUu

32. Answers: 1. RrYy: 2 n = 2 2 = 4 gametes RY Ry rY ry 2. AaBbCCDd: 2 n = 2 3 = 8 gametes ABCD ABCd AbCD AbCd aBCD aBCd abCD abCD 3. MmNnOoPPQQRrssTtUu: 2 n = 2 6 = 64 gametes

33. Autosomal Inherited Traits are inherited via the autosomes (non-sex) chromosomes. How many autosomes are in each of your somatic cells?

34. That’s right! There are 44 autosomes and 2 sex chro- mosomes in each of your somatic (non-sex) cells.

35. Figure 13.x5 Human male karyotype shown by bright field G-banding of chromosomes

36. Autosomal Inherited Genetic Disorders include: Cystic Fibrosis Tay-Sachs Disease Sickle Cell Anemia Huntington Disease (this one is dominant!)

37. Cystic Fibrosis Most common inherited fatal disorder in the U.S. Median age of death–37 One in every 29 Americans has the gene Mucus builds up in the lungs

39. Francis Collins, director the Human Genome Project, helped pioneer the discovery of the CF gene in 1989.

40. Boomer Esiason and his son, Gunnar, who has CF.

42. Diagnosis: Treatment:

43. CF is a great success story even though it is a terrible disease

44. Tay Sachs Disease a lipid-digesting enzyme is defective in lysosomes

45. If two parents are each carriers of the gene for Tay-Sachs Disease, what is the probability of them having a child with the disease?

46. That’s right! They have a 25% chance! T t T t TT Tt tt Homozygous Dominant Heterozygous Homozygous Recessive

47. Sickle Cell Anemia

49. Huntington Disease A degenerative disorder of the nervous system Most people don’t realize that they have the disease until after age 30 and may have passed on the gene

50. Caused by a stuttering gene - CAG repeat Also called Huntington’s Chorea This is a dominant gene

52. Nancy Wexler’s Pedigree of 10,000 people in Lake Maracaibo

54. Huntington Disease (chorea)

55. Some human traits are sex-linked; that is they are carried on the X and Y Chromosomes

56. For Example: Hemophilia, Duchenne Muscular Dystrophy, and Colorblindness are all traits carried on the X chromo- some

57. Hemophilia

58. Colorblindness

59. Duchenne Muscular Dystrophy

60. If a female who is carrier for Duchenne Muscular Dystrophy (D), what is the probability of she and her“normal”husband having a child with MD?

61. X Y D X D D d X D d X Y D d Male with Disease Carrier Female Normal

62. A pedigree shows the genetic relationship between organisms or people.

63. Bloodtypes are also inherited: A = has antigen A B = has antigen B O =neither AB =has both antigens A and B

64. Genotypes O = OO AB = AB A = AA or AO (codominance) B = BB or BO (codominance)

65. O is the universal donor (can donate blood to anyone) AB is the universal recipient ( can receive blood from anyone)

66. The Rh Factor is also inherited. Approximately 85% of Americans are positive for the Rh Factor. For example, if you have type A blood and are positive for the Rh Factor then your bloodtype is A positive.

67. So technically there are 8 blood groups: A positiveAB positive A negativeAB negative B positive O positive B negative O negative

68. In terms of a couple having kids, positive blood dominates negative blood. For example, a father with A positive blood and his wife with A negative blood would have kids with A positive blood.

69. RhoGAM A woman who is pregnant and is Rh negative and has an Rh positive child must take RhoGAM in order to not reject the child.

70. If a woman who is type B and a man who is type A have kids, what are their possible bloodtypes?

71. O A A AO WOMAN MAN

72. A O O O OO AO OO

73. In squash an allele for white color (W) is dominant over yellow (w). Give the phenotypic ratios for the results of each of the following crosses: W/W x w/w W/w x w/w W/w x W/w

74. If a brown eyed man marries a brown eyed woman and they have a blue eyed child, what are the genotypes of the parents?

75. If a man whose sister died of Cystic Fibrosis marries a woman who does not have the disease or any history of it in her family, what is the probability that they will have kids with the disease?

76. In pea plants, if purple flowers are dominant over white, and smooth seeds are dominant over wrinkled, predict the out- come of the crossing of a pea plant heterozygous for color and homozygous recessive for seed coat texture with one heterozygous for both traits.

77. What is the probability of a couple who are both heterozygous for widow’s peak (W) and free earlobes (F) having a child with neither trait?