2. Gregor Mendel (1822-1884) Responsible for the Laws governing Inheritance of Traits copyright cmassengale 3. Gregor Johann Mendel
copyright cmassengale 4. Gregor Johann Mendel
copyright cmassengale 5. Site of Gregor Mendels experimental garden in the Czech Republic copyright cmassengale 6.
Particulate Inheritance copyright cmassengale 7. Genetic Terminology
copyright cmassengale 8. Types of Genetic Crosses
copyright cmassengale 9. Punnett Square
copyright cmassengale 10. copyright cmassengale 11. DesignerGenes
copyright cmassengale 12. More Terminology
copyright cmassengale 13. Genotype & Phenotype in Flowers Genotype of alleles: R = red flower r = yellow flower All genes occur in pairs, so2 allelesaffect a characteristic Possible combinations are: Genotypes RR R r rr Phenotypes REDREDYELLOW copyright cmassengale 14. Genotypes
copyright cmassengale 15. Genes and Environment Determine Characteristics copyright cmassengale 16. Mendels Pea Plant Experiments copyright cmassengale 17. Why peas, Pisum sativum ?
copyright cmassengale 18. Reproduction in Flowering Plants
copyright cmassengale 19. Mendels Experimental Methods
copyright cmassengale 20. How Mendel Began Mendel producedpurestrains by allowing the plants toself-pollinatefor several generations copyright cmassengale 21. Eight Pea Plant Traits
copyright cmassengale 22. copyright cmassengale 23. copyright cmassengale 24. Mendels Experimental Results copyright cmassengale 25.
The theoretical or expected ratio of plants producing round or wrinkled seeds is3 round :1 wrinkled Mendels observed ratio was 2.96:1 The discrepancy is due tostatistical error Thelarger the samplethe more nearly the results approximate to the theoretical ratio copyright cmassengale 26. Generation Gap
copyright cmassengale 27. Following the Generations Cross 2 Pure Plants TT x tt Results in all Hybrids Tt Cross 2 Hybrids get 3 Tall & 1 Short TT, Tt, tt copyright cmassengale 28. Monohybrid Crosses copyright cmassengale 29.
P 1Monohybrid Cross R R r r Rr Rr Rr Rr Genotype: Rr Phenotype : Round Genotypic Ratio: All alike Phenotypic Ratio:All alike copyright cmassengale 30. P 1Monohybrid Cross Review
copyright cmassengale 31.
F 1Monohybrid Cross R r r R RR rr Rr Rr Genotype: RR, Rr, rr Phenotype : Round & wrinkled G.Ratio: 1:2:1 P.Ratio: 3:1 copyright cmassengale 32. F 1Monohybrid Cross Review
copyright cmassengale 33. What Do the Peas Look Like? copyright cmassengale 34. And Now the Test Cross
copyright cmassengale 35.
F 2Monohybrid Cross (1 st ) R R r R RR Rr RR Rr Genotype: RR, Rr Phenotype : Round Genotypic Ratio: 1:1 Phenotypic Ratio:All alike copyright cmassengale 36.
F 2Monohybrid Cross (2nd) r r r R Rr rr Rr rr Genotype: Rr, rr Phenotype : Round & Wrinkled G. Ratio: 1:1 P.Ratio:1:1 copyright cmassengale 37. F 2Monohybrid Cross Review
copyright cmassengale 38. Practice Your Crosses
copyright cmassengale 39. Mendels Laws copyright cmassengale 40. Results of Monohybrid Crosses
copyright cmassengale 41. Law of Dominance In a cross of parents that arepure for contrasting traits , only one form of the trait will appear in the next generation. All the offspring will be heterozygous and express only thedominant trait. RR x rryieldsall Rr (round seeds) copyright cmassengale 42. Law of Dominance copyright cmassengale 43. Law of Segregation
copyright cmassengale 44. Applying the Law of Segregation copyright cmassengale 45. Law of Independent Assortment
copyright cmassengale 46. Dihybrid Cross
copyright cmassengale 47. Question: How many gametes will be produced for the following allele arrangements?
copyright cmassengale 48. Answer: 1.RrYy:2 n= 2 2= 4 gametes RYRyrYry 2.AaBbCCDd:2 n= 2 3= 8 gametes ABCDABCdAbCDAbCd aBCDaBCdabCDabCD 3.MmNnOoPPQQRrssTtQq:2 n= 2 6= 64 gametes copyright cmassengale 49. Dihybrid Cross
RrYyxRrYy RY Ry rY ry RY Ry rY ry All possible gamete combinations copyright cmassengale 50. Dihybrid Cross copyright cmassengale RY Ry rY ry RY Ry rY ry 51. Dihybrid Cross copyright cmassengale RRYY RRYy RrYY RrYy RRYy RRyy RrYy Rryy RrYY RrYy rrYY rrYy RrYy Rryy rrYy rryy Round/Yellow:9 Round/green:3 wrinkled/Yellow:3 wrinkled/green:1 9:3:3:1 phenotypic ratio RY Ry rY ry RY Ry rY ry 52. Dihybrid Cross Round/Yellow:9 Round/green:3 wrinkled/Yellow: 3 wrinkled/green:1 9:3:3:1 copyright cmassengale 53. Test Cross
copyright cmassengale bC b___ bc 54. Test Cross
copyright cmassengale bC b___ bc bbCc bb C c C bC b___ bc bbCc bb c c or c 55. Summary of Mendels laws copyright cmassengale LAW PARENT CROSS OFFSPRING DOMINANCE TT x tt tall x short 100% Tttall SEGREGATION Tt x Tt tall x tall 75% tall25% short INDEPENDENT ASSORTMENT RrGg x RrGg round & green xround & green 9/16 round seeds & green pods3/16 round seeds & yellow pods3/16 wrinkled seeds & green pods1/16 wrinkled seeds & yellow pods 56. Incomplete Dominance and Codominance copyright cmassengale 57. Incomplete Dominance
copyright cmassengale R R r r 58. Incomplete Dominance r copyright cmassengale Rr Rr Rr Rr R R r All Rr =pink (heterozygous pink) produces the F 1generation 59. Incomplete Dominance copyright cmassengale 60. Codominance
copyright cmassengale 61. Codominance Problem
copyright cmassengale I A I B I B i I A I B I B i 1/2 =I A I B 1/2 =I B i I B I A i I B 62. Another Codominance Problem
copyright cmassengale I A i I B i I A i I B i 1/2 =I A i 1/2 =I B i i I A I B i 63. Codominance
copyright cmassengale 64. Codominance
Parents: genotypes =I A iandI B i phenotypes =AandB copyright cmassengale I A I B ii I B I A i i 65. Sex-linked Traits
copyright cmassengale 66. Sex-linked Traits Sex Chromosomes Example:Eye color in fruit flies copyright cmassengale XX chromosome - female Xy chromosome - male fruit fly eye color 67. Sex-linked Trait Problem
copyright cmassengale X R X r X r Y 68. Sex-linked Trait Solution: 50%red eyed female 50%white eyed male copyright cmassengale X RX r X rY X RX r X rY X R X r X r Y 69. Female Carriers copyright cmassengale 70. Genetic Practice Problems copyright cmassengale 71. Breed the P 1generation
copyright cmassengale T T t t 72. Solution: tall (TT) vs. dwarf (tt) pea plants copyright cmassengale T T t t Tt Tt Tt Tt All Tt = tall (heterozygous tall) produces the F 1generation 73. Breed the F 1generation
copyright cmassengale T t T t 74. Solution: tall (Tt)xtall (Tt) pea plants copyright cmassengale TT Tt Tt tt T t T t produces the F 2generation 1/4 (25%) = TT 1/2 (50%) = Tt 1/4 (25%) = tt 1:2:1 genotype 3:1phenotype 75. copyright cmassengale