2. Do Now!! True or False?   1. Certain thoughts or experiences of a mother mark or alter the hereditary makeup of an unborn child.   2. Color blindness is more common in males than in females.   3. A person may transmit characteristics to offspring which he/she does not show.   4. Certain inherited traits may be altered by the stars, planets or moon early in development.   5. The total number of male births exceeds female births each year.

3.  Allele: Version of a gene  Dominant: shields recessive trait  (ex: B=brown eyes)  Recessive: masked by dominant  (ex: b=blue eyes)  Heterozygous: 2 different alleles  (ex: Bb)  Homozygous: 2 of the same alleles  (ex: BB, bb)  Genotype: organism’s set of genes  (ex: BB, Bb, bb)  Phenotype: physical appearance  (ex: brown or blue eyes)

5. Chapter 10: Genetics!

6. Objectives  To distinguish between heredity and inheritance  To describe Mendel’s experiments in heredity  To compare heterozygous vs. homozygous and dominant vs. recessive.

7. Say whaaat??  Maria and Lucy are bi-racial twins… how is this possible??  Let’s brainstorm…

8. Do Now!!  Ariel and Prince Eric are curious to see what their babies will look like! Eric is heterozygous for black hair and Ariel has the recessive trait of red hair. Both are recessive for blue eyes. If they have 32 children, how many can we EXPECT to have red hair and blue eyes?

9. Do Now!! Mickey Mouse is heterozygous for round ears and homozygous for black eyes. Minnie Mouse is homozygous for floppy ears and heterozygous for black eyes. Determine phenotype ratios.

10. Genetics: the study of heredity by which traits are passed from parents to offspring

11. Gregor Mendel o The father of genetics! o First to develop rules that accurately predict patterns of heredity o Discovered how traits were inherited in a population using pea plants

12. The beginning of genetics…  The passing of traits to the next generation – inheritance or heredity  Mendel performed cross-pollination and self- fertilization in pea plants  Mendel followed various traits in the pea plants he bred

13. 7 Traits Mendel Studied

14. Pollination: transfer of pollen from anthers to stigma in flowers 1) self pollination occurs within the same flower or same plant 2) cross pollination occurs between different plants

15. Mendel’s Crosses with Pea Plants Pure tall plants X Pure short plants P1P1 parental generation Cross Pollination All Tall plants F1F1 first filial generation Self Pollination 787 tall plants, 277 short plants F2F2 second filial generation 3 to 1 ratio

16. Generations  P Generation  Parents  Pure bred  F 1 Generation  Hybrid – 2 different types of genes for a trait  F 2 Generation  3:1 ratio

19. Mendel’s 3 Laws of Inheritance 1. Law of Dominance- Each trait is controlled by 2 factors: what is expressed Dominant- what is expressed Recessive- masked in presence of dominant P1P1 F1F1 F2F2

20. Mendel’s 3 Laws of Inheritance (cont.) 2. Law of Segregation- Each allele separates into different gametes (when does this happen??) Ex. Ww – one W goes in one sperm and the other w goes into another sperm Ww w W

21. Mendel’s 3 Laws of Inheritance (cont.) 3. Law of Independent Assortment- Gene pairs (homologous) will separate randomly into gametes during meiosis *Chromosomes line up randomly at metaphase plate

22. Do Now!! (P. 6)  What were the results of Mendel’s experiments for F1 and F2 generations?  What are his 3 laws?  What is a gene?

23. o Gene – segment of DNA on a chromosome that codes for a particular protein *genes occur in pairs Definitions

24. Allele – alternative form of a gene g = yellow pods G = green pods t = short T = tall Dominant capital letter (shields recessive trait) Recessive Lowercase letter (usually hidden)

25. More alleles!

26. (Ex: Blue eyes or Brown Eyes) Phenotype – physical characteristics of an organism

27. Genotype -genetic makeup of an organism (genes) -alleles received from parents (internal information Ex: BB, Bb, bb)

28. Genotype vs. Phenotype genotype phenotype TT Tall

29. Homozygous – when both alleles of a pair are the same homozygous dominant homozygous recessive TT tt

30. Heterozygous – when both alleles of a pair are not the same heterozygous (tall) Tt

31.  If Jon Snow is heterozygous for black hair… (H=Black, h=blonde)  1. What is Jon Snow’s genotype?  2. What is Jon Snow’s phenotype?  Beyonce is BB. (B= brown eyes, b=blue eyes)  1. What is her genotype?  2. What is her phenotype?  3. Is she heterozygous or homozygous? Explain.

32. Genotypic vs. Phenotypic Ratios  Phenotype Ratio:  Ratio of different physical traits  Ex) Brown eyes ¼ or 25%  Genotype Ratio:  Ratio of the different possible alleles  Ex) Tt = ¼ or 25%

33. Monohybrid Cross  R= Can roll your tongue  r= Can’t roll your tongue  Genotype Ratio:  Phenotype Ratio: Rr R r

34. Lets Try a Monohybrid together! 1)Daffy Duck is heterozygous for black feathers. Daisy Duck is homozygous for yellow feathers. Set up a punnett square and determine probabilities of their potential offspring. (Both genotype and phenotype ratios!) 2)B = Black b = yellow

35. DO NOW!! Sleeping Beauty has freckles. Her prince charming is heterozygous for no freckles. What are the chances of her children having freckles? Please show your work.

36. Test cross – an individual with unknown genotype is crossed with a homozygous recessive individual  used to determine the genotype of any individual whose phenotype is dominant

37. Lets Try a Test Cross  Spongebob squarepants doesn’t know whether or not he is Homozygous Dominant or Heterozygous for his yellow color. The recessive trait is a white sponge. Let’s say that we perform a “test cross” on spongebob (spongebob + a white female sponge) and all of the baby sponges are yellow. What would spongebob’s genotype be?

38. What is a dihybrid Cross?  A dihybrid cross allows us to predict possible outcomes of offspring that will have 2 traits simultaneously.  Ex: what would you get if you crossed a Brown- haired brown-eyed male with a blonde-haired blue-eyed female? How many of the children would have brown hair and brown eyes? Brown hair and blue eyes? Blonde hair and brown eyes? Blonde hair and blue eyes?

39. Setting up Dihybrid Crosses 1. Labels!! 2. Determine parent genotypes 3. Determine gametes (alleles to be passed down) The FOIL method 4. Set up punnet square 5. Determine outcome Phenotype Ratio

40. Dihybrid Crosses Looking at two different traits Ex. Hair color and eye color B=brown eyes b=blue eyes R=Brown hair r=blonde hair Mother is heterozygous for both traits Father is heterozygous for eye color and homozygous dominant for hair color

41. Example

42. More Practice Mickey Mouse is heterozygous for Round ears and homozygous for Black eyes. Minnie Mouse is homozygous for Floppy ears and heterozygous for Black eyes. Determine phenotype ratios. (B=black eyes, b=brown eyes, R=round, r= floppy.)

43. Gene Linkage  There are several genes on a chromosome  Gene Linkage:  When two genes are close to each other on the same chromosome

44. Gene Linkage (cont.) o Linked genes on a chromosome results in an exception to Mendel’s law of independent assortment o Linked genes usually do not segregate independently

45. Drosophila melanogaster (Fruit Flies) o First organism with linked genes o Linked genes typically travel together during crossing over

46. Chromosome Map  A map of genes on chromosomes  Crossing over occurs more frequently between genes that are far apart

47. Polyploidy o Cells that contain more than 2 homologous sets of chromosomes o Ex. A triploid organism (3n) - means that it has three complete sets of chromosomes. Strawberries are octoploid!!

48. Pedigree  Shows history of a trait in a family  Allows researchers to analyze traits within a family

49. In a pedigree…  You can see how a genetic disorder runs in a family.  Carriers are individuals who are heterozygous for an inherited disorder but do not show symptoms.  Carriers can pass the allele for the disorder to their offspring

50. Symbols for Pedigree

52. Worksheet!!

53. Do Now!!  Fill in the genotypes for the following pedigree (shows recessive trait)  B=brown eyes  b = blue eyes

54. Incomplete dominance

56.  Both traits are dominant and expressed (no blending)  Ex: Roan Cows  white hair (H W ) is codominant with red hair (H R )  cows with genotype (H R H W ) have coats with a mixture of red and white hairs (roan)  Red + White = RED AND WHITE

57. Do Now!!  What is the difference between incomplete and codominance?  Cross a roan cow with a red cow.

58. Multiple alleles – 3 or more alleles that control a trait  Example: blood type!  Possible alleles: I A, I B, i  Which genotypes are heterozygous? Homozygous? GENOTYPESRESULTING PHENOTYPES IAIAIAiIAIAIAi Type A IBIBIBiIBIBIBi Type B IAIBIAIB Type AB iiType O

59. Antigens vs. Antibodies  Antigen: substance foreign to the body that causes an immune response:  Can act as surface markers  EX: type A antigens on surface of type A blood cells  Antibody: protein that reacts with specific antigen:  EX: Type B blood contains anti-A antibodies

60. Which is the universal donor? Universal acceptor?

61. Determine Blood Type  Determine the possible offspring of the following crosses  1. AB and O  2. Homozygous A and heterozygous B  3. AB and AB

62. What do you see?

64. Sex Linked Traits  Traits located on the sex chromosomes (X or Y)  X linked: gene is located on the X chromosomes  Y linked: gene is located on the Y chromosome  Ex: color-blindness is X-linked! *If X-linked, can males be carriers?

66. What are the chances of having a girl?  How would you go about solving it?

67. Sex-Linked Traits  A man who is color blind marries a woman that is heterozygous for color blindness. What is the chance of having a color blind boy?

68. Polygenic Traits o Polygenic traits arise from the interaction of multiple pairs of genes.

69. Worksheet!!