1. Ch. 10.1 Mendel’s Discoveries

2. Gregor Mendel (1866) “Father of Modern Genetics” Breed pea plant. (Pre- Mendel: Blending of traits hypothesis)

3. Background Vocab  True-breeds: pure gene lines – offspring match parent  Self-pollination: pollen from flower fertilizes the same plant  Cross-fertilization: pollen will fertilize a different plant  Hybrid: Cross between organisms with different traits (blonde hair & brown hair)  Trait: Physical characteristics

4. 5/20/20154 Cross pollination

6. 6 Trait StudiedDominant Form Recessive Form F 2 Dominant-to- Recessive Ratio SEED SHAPE SEED COLOR POD SHAPE POD COLOR FLOWER COLOR FLOWER POSITION STEM LENGTH 2.96:1 3.01:1 2.95:1 2.82:1 3.15:1 3.14:1 2.84:1787 tall277 dwarf 651 long stem207 at tip 705 purple224 white 152 yellow428 green 299 wrinkled882 inflated 6,022 yellow2,001 green 5,474 round1,850 wrinkled

7. Mendel’s Experimental design 5/20/2015 Parental generation (P) White X Purple (truebreed X truebreed) Offspring: F1 Generation (Hybrids) 100% purple F1 Cross Purple X Purple (hybrid X hybrid) Offspring: F2 (3:1 – Purple : White) 75% Dominant: 25% Recessive

8. Mendel’s Conclusions: Inheritance is determined by chemical factors (genes) passed from one generation to the next (particulate hypothesis) Genes can come in more than one form= allele Example: (white vs purple)

9. Ch. 10.2 Mendel’s Genetics

10. More Genetics Vocab Homozygous: two identical alleles (AA or aa) Heterozygous: two different alleles (Aa) Phenotype: Physical appearance Genotype: Genetic make-up –Homozygous dominant (AA) –Homozygous recessive (aa) –Heterozygous (Aa)

11. Mendel’s Principles 1.There are alternative forms of genes (alleles) 2.There are 2 alleles for each trait (BB,Bb, bb) * we now know there can be more. 3.Some alleles are dominant; some recessive. 4.Principle of SEGREGATION: Alleles for each trait segregate (separate) during gamete formation (Anaphase I of meiosis)

13. Monohybrid Crosses = Parents differ in only 1 trait P: Purple X White F1: all purple (100% dominant) F1 purples self- fertilize to see if white trait was lost. F2: 75% purple; 25% white (dominant) (recessive)

14. Diagram that shows all possible outcomes of a genetic cross

15. Standard Mendelian Cross #1: Standard Mendelian Cross #1: If purple flower color is dominant, what phenotypes are expected if a purebred purple flowered plant is crossed with a purebred white flowered plant? 5/20/201515 WWww WW x ww Phenotypic Ratio: 100% purple Genotypic ratio: 100% Ww

16. Standard Mendelian Cross #2: Standard Mendelian Cross #2: If purple flower color is dominant, what genotypes are expected if a heterozygote is crossed with another heterozygote. 5/20/201516 WwWw Ww x Ww Phenotypic ratios: 3 purple: 1 white Genotypic ratios: 1WW:2Ww:1ww

17. Testcross: Helps determine the genotype of a dominant phenotype Dominant phenotype could be AA or Aa Unknown Dominant X Recessive (aa) -Any recessive offspring, unknown= Aa -All dominant offspring, unknown= AA

20. Mendel’s DIHYBRID CROSSES (2 traits) Independent Assortment: Alleles for different traits do not influence each other’s segregation during meiosis.

21. List the gamete combinations possible for each of the genotypes listed below: 5/20/201521 RrYY rrYY RrYy RY, rY, RY, rY rY, rY, rY, and rY RY, Ry, rY, and ry

22. Dihybrid Cross F2: 9:3:3:1 Ratio Traits are inherited separately.

25. Black hair is dominant to white Short hair is dominant to long Cross a heterozygous black & short haired mouse with a white & heterozygous short haired mouse. 1. What are the genotypes of the parents? 2. What are the genotypic and phenotypic ratios of the F1 generation?

26. 10.3 Exceptions to Mendel

27. Incomplete/Intermediate dominance: blending of phenotypes neither allele takes a fully dominant role P1: Red x White flowers F1: Pink flowers F2: 1 red: 2 pink: 1 white

29. Codominance BOTH alleles are expressed in heterozygotes. Not incomplete dominance EX: Roan cattle and Blood types

31. Multiple Alleles More than 2 alleles for an inherited character. Eye color Blood type: A, B, AB, or O Fur color

32. Blood Typing: Multiple Allelism a)Human blood type is expressed by 3 alleles: I A, I B and i. b)I A and I B are Co-dominant c) i is recessive.

33. Codominance in blood groups 5/20/201533

35. Blood Type: Codominance & Multiple Alleles

36. CaucasiansAfrican American HispanicAsian O +37%47%53%39% O -8%4% 1% A +33%24%29%27% A -7%2% 0.5% B +9%18%9%25% B -2%1% 0.4% AB +3%4%2%7% AB -1%0.3%0.2%0.1%

38. Could a person with Type A blood receive type O blood? Could they receive Type AB? Could a person with AB- blood receive AB+? List the blood types that type B+ could receive?

39. Polygenic Inheritance: Multiple Genes affect a trait continuous variation Phenotypes of these traits demonstrate continuous variation (bell curve) Examples: Examples: height, weight, skin color, intelligence. 39

40. Continuous variation in skin color 5/20/201540

41. Environmental Influence on Genes Temperature, pressure, pH, presence of certain chemical compounds influence how genes are expressed. Epigenetics: study of how genes are influenced by environmental conditions.

42. Environmental Influence 1.Some flowers colors are influenced by the acidity of the soil (Hydrangea). 1.The color of the arctic fox is influenced by temperature. 2.Siamese cats have darker hair at areas that are cooler than body temperature (ears, nose and paws). 3.Human size is influenced by nutrition. 42

43. 10.5: Sex Linked Genes: Genes located on X or Y chromosome

44. Do you think the X chromosome or the Y chromosome holds more genes?

45. Rules 1. Recessive Sex Linked Traits: - Affect males more than females - Males only need one copy of the gene (X a Y). - Females can be carries (X A X a ) 2. Dominant Sex- Linked Traits: - More likely to affect females (X A X A or X A X a )

46. Recessive Sex-Linked Disorders  Color-blindness  Hemophelia  Baldness  Versions of Muscular Dystrophy

47. 12.3- Pedigrees

49. A Pedigree is a family tree that shows the inheritance of a genetic disorder Carriers: do not have the disorder but can pass it on (heterozygous)

50. A pedigree can allow you to determine whether a trait is autosomal, or sex-linked. 1.Autosomal 1.Autosomal disorders affect males and females equally. autosomal dominantevery individual at least one parent 1.If the trait is autosomal dominant, every individual who has the disorder will have at least one parent who has the disorder. autosomal recessive one, two or neither parent 2.If the trait is autosomal recessive, an individual with the trait can have one, two or neither parent exhibit the trait.

51. 1.Sex-linked traits are carried on the X chromosome, and therefore affect one gender or the other in disproportionately high numbers. a)Sex-linked recessive traits affect males in higher numbers. Since they have only one X chromosome, if males receive a single copy of this recessive allele, they will show the phenotype. Females must still receive two recessive versions to show the phenotype. b)Sex-linked dominant traits affect females in higher numbers A female has two X chromosomes, and therefore is twice as likely to receive the trait

52. 5/20/201552

53. 5/20/201553

54. 5/20/201554 Question: Is this disorder autosomal or sex-linked? Is it dominant or recessive? Parents are unaffected Both males and females are affected

55. Complete the following pedigrees. Which is for a sex-linked trait? How do you know? Is it a dominant or recessive trait?

56. Royal Family Pedigree

57. Human genetic disorders 5/20/201557

58. 10.4 Gene linkage

60. Genes located on the same chromosome tend to be linked Loci: location of a gene on a chromosome

61. Gene Linkage: Gene closer together on chromosome have a greater likelihood of traveling together during crossing over Greater likelihood of inheriting genes together

62. 12.1 Genome: the complete set of genetic material

63. 12. 4- Genes and Cancer

64. Regulation of Cell Cycle –Growth factors: Initiate cell division –Tumor Suppressor Genes: Stop Cell Division Cancer is ALWAYS a genetic disease due to mutations in DNA –Mutation in somatic cells= not passed on to offspring –If mutation occurs in ovaries or testes offspring will inherit an abnormal copy of a gene that increases their likelihood of developing cancer

65. Epigenetics NOVA Video NOVA Video (13min)