1. Hold off on ch 9 vocab…let’s make it due the day of the test (4/9??)!!!

2. Some similarities are not genetic

5. Many similarities are considered genetic

6. Twins!

8. What about within a family?

9. What is genetics? Genetics is the study of inheritance of genes. Heredity is the passing of traits from parent to offspring.

10. We now know that genes on chromosomes control an organisms form and function. The different forms of a gene that control a trait are called alleles. (Notice the two alleles above: D and d).

11. The Father of Genetics: Gregor Mendel

12. Mendel (1822-1884)was an Austrian Monk who studied mathematics and science. Mendel was curious about the inheritance of pea plant characteristics. He began experimenting with pea plants in 1856.

13. Fig. 14-1

14. Why pea plants? 1.CHEAP…..remember he was a monk 2.Easy to grow 3.Self fertilize 4.Cross Breeding

15. Pea plant flower anatomy

16. Self Pollination If a pea plant is self-pollinated, pollen from the anther is transferred to the stigma of the same plant.

17. Crosspollination occurs when pollen from one pea plant is transferred to the stigma of another pea plant.

18. Fig. 14-2 TECHNIQUE RESULTS Parental generation (P) Stamens Carpel 1 2 3 4 First filial gener- ation offspring (F 1 ) 5

19. Mendel chose to track only those characters that varied in an either-or manner He also used varieties that were true-breeding (plants that produce offspring of the same variety when they self-pollinate)

20. Gregor Mendel Mated 2 true breeding varieties of pea plant 1 true breed tall and 1 true breed short All offspring came out ……………

21. TALL!

22. Fig. 14-3-1 EXPERIMENT P Generation (true-breeding parents) Purple flowers White flowers 

23. Fig. 14-3-2 EXPERIMENT P Generation (true-breeding parents) Purple flowers White flowers  F 1 Generation (hybrids) All plants had purple flowers

24. Then Mendel crossed 2 of the Tall offspring from this cross and the results came out……………………… 3Tall1Short

25. Fig. 14-3-3 EXPERIMENT P Generation (true-breeding parents) Purple flowers White flowers  F 1 Generation (hybrids) All plants had purple flowers F 2 Generation 705 purple-flowered plants 224 white-flowered plants

26. In a typical experiment, Mendel mated two contrasting, true-breeding varieties, a process called hybridization The true-breeding parents are the P generation The hybrid offspring of the P generation are called the F 1 generation When F 1 individuals self-pollinate, the F 2 generation is produced Copyright © 2008 Pearson Education Inc., publishing as Pearson Benjamin Cummings

27. Important Terminology Genotype Phenotype Heterozygous Homozygous Autosomal Trait Sex Linked Trait

28. Mendel’s actual results

29. Mendel’s Conclusions From these results, Mendel concluded that: Genes controlling heredity occur in pairs. One allele (dominant) in a pair masked the other (recessive) preventing it from showing its affect. This became known as the principle (law) of dominance.

30. Mendel’s First Law: The Law of Segregation During the formation of gametes (sex cells), paired alleles (genes) separate so that each gamete carries one allele for each trait.

32. © 2011 Pearson Education, Inc.

33. Practice Problem: Cross a pure tall pea plant with a pure short pea plant F1F1

34. Now, self-pollinate the F 1 F2F2 Phenotypes

35. Practice Monohybrid Crosses

37. Dihybrid Cross Mendel was able to construct dihybrid cross to explain the principle of independent segregation. Just because a pea is yellow and round or green and wrinkled…these 2 traits are not necessarily transferred together.

38. P generation 1–21–2 Hypothesis: Dependent assortment Hypothesis: Independent assortment 1–21–2 1–21–2 1–21–2 1–41–4 1–41–4 1–41–4 1–41–4 1–41–4 1–41–4 1–41–4 1–41–4 9 –– 16 3 –– 16 3 –– 16 1 –– 16 RRYY Gametes Eggs F 1 generation Sperm F 2 generation Eggs Gametes rryy RrYy ry RY ry RY ry RY Hypothesized (not actually seen) Actual results (support hypothesis) RRYY rryy RrYy ry RY RRYY rryy RrYy ry RY RrYy rrYYRrYY RRYyRrYY RRYy rrYy Rryy RRyy rY Ry ry Yellow round Green round Green wrinkled Yellow wrinkled RY rY Ry

39. Practice Dihybrid Crosses

40. 9.7 Mendel’s laws reflect the rules of probability  The probability of a specific event is the number of ways that event can occur out of the total possible outcomes.  Rule of multiplication Multiply the probabilities of events that must occur together  Rule of addition Add probabilities of events that can happen in alternate ways Copyright © 2009 Pearson Education, Inc.

41. Multiple Alleles Sometimes more than 2 different versions of the alleles exist.

42. Human blood type is controlled by multiple alleles. What are the three alleles that control human blood type? A, B, and O A and B are codominant (neither allele dominates the other) O is recessive to both A and B.

43. Blood type is determined by the type of antigen present on the surface of red blood cells (RBCs).

44. Human blood type can be A, B, AB or O. A antigen B antigenAB antigen Neither antigen (O)

45. Mental Note: Why is it important to know blood types? Your immune system could reject foreign blood cells. Therefore, transfusing foreign bloods cells could be dangerous.

46. Blood tissue also has antibodies circulating in it. Antibodies destroy foreign antigens.

48. Blood Group Antigens on RBCs Antibodies in bloodGenotypes AAAnti-BI A I A or I A i BBAnti-AI B I B or I B i ABA and BNeitherIAIBIAIB O Anti-A and anti-B i

49. What happens when you mix incompatible blood types?

50. Which blood type is the universal donor type? O type Why? Because O type red blood cells do not have any antigens on their surface for antibodies to attack. This blood can be transfused into anyone. Which blood type is the universal recipient type? AB type Why? Because a person with AB blood type does not produce anti- A or anti-B antibodies. A person with this blood type can receive blood from anyone.

51. Cross a female that is heterozygous for B type blood with a man that is heterozygous for A type blood and determine the kinds of offspring they could have. I A i x I B i

52. In addition to the ABO blood antigens, there are other red blood cell antigens including the Rh (rhesus) factor. – Rh positive means having the Rh antigen on a RBC. – Rh negative means not having it. – Rh positive is dominant.

53. Rh positive genotype + + or + - Rh negative genotype -

55. I A I A + + I A i + + I A I A + - I A i + - Possible genotypes I A I A - - I A i - -

56. Possible genotypes I B I B + + I B i + + I B I B + - I B i + - I B I B - - I B i - -

57. Possible genotypes i i + + i i + - i i - -

58. Problem: if a man is I A i negative and his wife is I A I B positive (heterozygous), what kinds of blood types can their children can they have? P 1 I A i - - x I A I B + -

59. Blood Type Rh Type How Many Have It Percentage O+1 person in 3 37.4% 44% O-1 person in 156.6% A+1 person in 335.7% 42% A-1 person in 166.3% B+1 person in 128.5% 10% B-1 person in 671.5% AB+1 person in 293.4% 4% AB-1 person in 167.6%

60. So who determines the sex????????????????

61. Sex determination Each human egg contains one X chromosome and each human sperm contains either one X or one Y chromosome. X X Eggs X Y Sperm

62. Which chromosome determines sex, the X or the Y? X X X Y

63. Fig. 15-6 44 + XY Parents 44 + XX 22 + X 22 + X 22 + Y or + 44 + XX or Sperm Egg 44 + XY Zygotes (offspring) (a) The X-Y system 22 + XX 22 + X (b) The X-0 system 76 + ZW 76 + ZZ (c) The Z-W system 32 (Diploid) 16 (Haploid) (d) The haplo-diploid system

64. Sometimes there is only one type of sex chromosome x

65. Fig. 15-6b (b) The X-0 system 22 + XX 22 + X Only one type of sex chromosome

66. Sometimes its ladies choice ZZ OR ZW

67. Fig. 15-6c (c) The Z-W system 76 + ZW 76 + ZZ

68. Sometimes its all about the numbers

69. Fig. 15-6d (d) The haplo-diploid system 32 (Diploid) 16 (Haploid)

70. Sex Linked Inheritance Color blindness Hemophilia Male pattern baldness Duchenne Muscular Dystrophy

71. III. Sex-Linked Recessive Inheritance Any genes that exist on the X chromosome are referred to as sex-linked or x-linked. Since the Y chromosome is much smaller than the X chromosome, the greater majority of the genes on the X chromosome are not on the Y chromosome.

72. Females carry two copies of all X-linked genes while males carry only one (males are hemizygous for genes on the X chromosome) Males need to inherit only one copy of a X-linked gene to manifest its phenotype, whereas females need to inherit two copies. What does this mean?

73. Examples of X-linked traits Red –green color-blindness Hemophilia Muscular Dystrophy Color blindness geneColor blindness gene

74. Symbols for sex-liked genes Female who is colorblind : X c X c Female who is heterozygous (carrier) for colorblindness (she has normal vision): X C X c Female with normal vision and not a carrier: X C X C Male who is color blind: X c Y Male who has normal vision: X C Y Note: a male can not be a carrier for a X-linked genetic disorder!

75. Can you read the number in the figure below?

77. Genetics Problems: Suppose that a woman was colorblind and her husband had normal vision. What percent of their children would be colorblind?

78. Suppose that a woman was a carrier for color- blindness and her husband had normal vision. What percent of their children would be colorblind?

79. Suppose that a man was hemophilic and his wife was not. What percent of their children would be hemophilic?