copyright cmassengale 1 Welcome Back to Biology! 2 nd Semester Last Semester Recap! Expectations Cell Phones Seating Charts Syllabus Let’s Get Started!

2 Joke of the Day:

3 Unit 8: Genetics Mendelian Genetics copyright cmassengale

4 Gregor Mendel ( ) “Father of Genetics“ Responsible for the Laws governing Inheritance of Traits copyright cmassengale

5 Gregor Johann Mendel  Austrian monk  Studied the inheritance of traits in pea plants  Developed the laws of inheritance  Mendel's work was not recognized until the turn of the 20th century copyright cmassengale

6 Gregor Johann Mendel  Mendel grew and tested some 28,000 pea plants  He found that the plants' offspring retained traits of the parents copyright cmassengale

7 Eight Pea Plant Traits Seed shape --- Round (R) or Wrinkled (r) Seed Color ---- Yellow (Y) or Green ( y ) Pod Shape --- Smooth (S) or wrinkled ( s) Pod Color --- Green (G) or Yellow (g) Seed Coat Color ---Gray (G) or White (g) Flower position---Axial (A) or Terminal (a) Plant Height --- Tall (T) or Short (t) Flower color --- Purple (P) or white ( p ) copyright cmassengale TraitsAlleles

8  Mendel stated that physical traits are inherited as “particles”  Mendel did not know that the “particles” were actually Chromosomes & DNA Particulate Inheritance copyright cmassengale

9 Site of Gregor Mendel’s experimental garden in the Czech Republic copyright cmassengale

10 Genetics – Study of Heredity copyright cmassengale

11 Heredity - Passing of traits from parent to offspring copyright cmassengale

12 Gene: Segment of DNA that codes for a Trait

13 Trait: Characteristic or Attribute Examples: Flower Color or Hair Color Flower Color or Hair Color

14 Genotype: Genetic makeup for a Trait (code). Examples: (RR, Rr, rr)

15 Phenotype – Trait resulting from a Genotype Examples: (“Brown” Hair, “Blue” Eyes, “Tall”, “Short”)

16 Designer “Genes” Alleles - Different forms of a Gene Example: (R, r) Dominant Dominant Stronger of two genes; represented by a capital letter. example: (R) Recessive Recessive Weaker of two genes; represented by a lowercase letter. example: (r)

17 Homozygous: “Purebred” 2 DOMINANT or 2 recessive Alleles Example: (RR or rr) 2 DOMINANT or 2 recessive Alleles Example: (RR or rr) Heterozygous: “Hybrid” 1 DOMINANT & 1 recessive Allele 1 DOMINANT & 1 recessive Allele Example: (Rr) copyright cmassengale

18 Genotype & Phenotype in Flowers Alleles: R = red flower r = yellow flower All genes occur in pairs, so 2 alleles affect a characteristic Possible combinations are: GenotypesRR Rrrr Phenotypes Red Red Yellow

19 Punnett Square Tool to show Allele combinations that might result from a genetic cross Letters on the outside represent the Genotypes of the parents Letters on the inside represent the Genotype possibilities of the offspring

copyright cmassengale 20

21 copyright cmassengale Monohybrid Cross

copyright cmassengale 22 Ratio: A comparison of two numbers : 1 1

copyright cmassengale 23 Ratio: A comparison of two numbers : 2 1

copyright cmassengale 24 Ratio: A comparison of two numbers : 2 2 : 1 1

copyright cmassengale 25 Ratio: A comparison of two numbers : 3 2

copyright cmassengale 26 Ratio: A comparison of two numbers :1 2 : 1

copyright cmassengale 27 Ratio: A comparison of two numbers : 1 0

28 Cross involving a single trait Example: flower color Monohybrid Cross

29 Trait: Seed Shape Alleles: R – Roundr – Wrinkled Cross: Round seeds x Wrinkled seeds RR x rr Monohybrid Cross: #1 R R r r Rr Genotypes:Rr Genotypes: Rr PhenotypesRound Phenotypes: Round Genotype Ratio: 100% Phenotype Ratio: 100%

30 Trait: Seed Shape Alleles: R – Roundr – Wrinkled Cross: Round seeds x Round seeds Rr x Rr Monohybrid Cross: #2 R r r R RR rrRr Genotypes:RR, Rr, rr Genotypes: RR, Rr, rr Phenotypes Round & Wrinkled Phenotypes: Round & Wrinkled Genotype Ratio:1:2:1 Genotype Ratio: 1:2:1 Phenotype Ratio: 3:1

31 Trait: Seed Shape Alleles: R – Roundr – Wrinkled Cross: Round seeds x Round seeds RR x Rr Monohybrid Cross: #3 R R r R RR RrRR Rr Genotypes:RR, Rr Genotypes: RR, Rr PhenotypesRound Phenotypes: Round Genotype Ratio:1:1 Genotype Ratio: 1:1 Phenotype Ratio: 100%

32 Trait: Seed Shape Alleles: R – Roundr – Wrinkled Cross: Wrinkled seeds x Round seeds rr x Rr Monohybrid Cross r r r R Rr rrRr rr Genotypes:Rr, rr Genotypes: Rr, rr Phenotypes Round & Wrinkled Phenotypes: Round & Wrinkled Genotype Ratio:1:1 Genotype Ratio: 1:1 Phenotype Ratio: 1:1

Bell Ringer : Bird Cross 33 Trait: Feather Color Alleles:Grey (G) White (g) Cross a homozygous dominant bird with a heterozygous bird Genotype Possibilities? Phenotype Possibilities? Genotype Ratio? Phenotype Ratio?

Bell Ringer: Define Gene: Define Trait: Define Allele: Define Homozygous: Define Heterozygous: Define Genotype: Define Phenotype: ***You will also have 2 Monohybrid Cross Problems Next…… 34

35 Trait: Feather Color Alleles: G – Greyg – White Cross: Grey Feathers x Grey Feathers GG x Gg Bell Ringer: Monohybrid Cross Bell Ringer: Monohybrid Cross G G gG GG GgGG Gg Genotype:GG, Gg Genotype: GG, Gg PhenotypeGrey Phenotype: Grey Genotype Ratio:1:1 Genotype Ratio: 1:1 Phenotype Ratio: 100%

36 Trait: Hair Texture Alleles: F – Finef – Course Cross: Cross a hybrid fine haired mouse with a mouse that is heterozygous for fine hair. Ff x Ff Ff x Ff Bell Ringer: Mouse Monohybrid Cross Bell Ringer: Mouse Monohybrid Cross F f fF FF ffFf Phenotype Ratio: 3:1 Genotypes: Genotypes: FF, Ff, ff Phenotypes Phenotypes: Fine and Course Genotype Ratio:1:2:1 Genotype Ratio: 1:2:1

Joke of the Day: 37

Bikini Bottom Genetics 38 Bikini Bottom Genetics 1 & 2 Due Today! Staple them together and put in the basket.

Joke of the Day: 39

40 Mendel’s Laws

41 Law of Dominance Examples: - Brown Hair is dominant over blonde. - Curly hair is dominant over straight Some alleles are dominant and others are recessive

42 Law of Dominance

43 Law of Segregation In Gametes (eggs or sperm), two alleles responsible for a trait separate from each other. Alleles are then "recombined" at fertilization, producing the genotype for the traits of the offspring Alleles are then "recombined" at fertilization, producing the genotype for the traits of the offspring.

44 Applying the Law of Segregation copyright cmassengale

45 Law of Independent Assortment Genes for different traits can segregate independently during the formation of gametes. (Genes don’t influence each other) copyright cmassengale

The likelihood that a particular event will occur Principle of Probability Can be used to predict the outcomes of genetic crosses.

47 Dihybrid Cross: copyright cmassengale

48 Dihybrid Cross: copyright cmassengale Cross involving two traits Example: flower color & plant height Example: flower color & plant height

49 Dihybrid Cross Traits: Seed shape & Seed color Alleles: Alleles: R round r wrinkled Y yellow y green RrYy x RrYy RY Ry rY ry All possible gamete combinations Round/Yellow x Round/Yellow Use F.O.I.L.

50 Dihybrid Cross RYRyrYry RYRy rY ry copyright cmassengale

51 Dihybrid Cross 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 Phenotype Ratio RYRyrYryRY Ry rY ry copyright cmassengale

52 Dihybrid Cross Round/Yellow: 9 Round/green: 3 wrinkled/Yellow: 3 wrinkled/green: 1 9:3:3:1 copyright cmassengale

Bellringer: On the white board copyright cmassengale 53

Special Genetic Cases: copyright cmassengale 54

Picture Joke of the Day: copyright cmassengale 55

Picture Joke of the Day: copyright cmassengale 56

Special Genetic Cases: copyright cmassengale 57

58 Incomplete Dominance Definition: One allele is not completely dominant over another. copyright cmassengale Red + White = Pink

59 Incomplete Dominance RWRWRWRW R RW Genotypes: RW Genotype Ratio: 100% RW Phenotypes: Pink Phenotype Ratio: 100% Heterozygous Pink W Trait: Flower Color Red (R): Dominant White (W): Dominant Homozygous Dominant Red (RR) X Homozygous Dominant White (WW)

60 Codominance Definition: Both alleles are visible in the phenotype of the organism. AB Blood Roan Cattle AB Blood Roan CattleExamples: Erminette Chickens Erminette Chickens (Speckled) (Speckled) Camellia Flower Camellia Flower copyright cmassengale

61

62 Codominance Problem Homozygous Black (BB) – Male X Homozygous White (WW) - Female BW Genotypes: BW Genotype Ratio:100% BW Phenotypes: Speckled Phenotype Ratio: 100% Heterozygous Speckled W B B W Trait: Chicken Color Black (B): Dominant White (W): Dominant Erminette Chicken

63 Another Codominance Problem male heterozygous (BW) x female heterozygous (BW) BBBW WW B BW W copyright cmassengale Genotypes: BB, WW, BW Genotype Ratio:1:2:1 Phenotypes: Black, White, Speckled Phenotype Ratio: 1:2:1

Joke of the Day: 64

copyright cmassengale 65 Sex-linked Traits Examples Eye color in Fruit Flies Hemophilia Color Blindness

66 Sex-linked Traits XX: genotype for females XY: genotype for males Many sex-linked traits carried on X chromosome The Y chromosome in males does not carry traits. copyright cmassengale Traits (genes) located on the sex chromosomes X and Y

67 Sex-linked Traits Sex Chromosomes XX chromosome - femaleXy chromosome - male fruit fly eye color Example: Eye color in fruit flies copyright cmassengale

68 Sex-linked Trait Problem Trait: Eye color in fruit flies (red-eyed male) x (white-eyed female) X R Y x X r X r RR = red eyed Rr = red eyed rr = white eyed XY = male XX = female XRXR XrXr XrXr Y copyright cmassengale

69 Sex-linked Trait Solution: X R X r X r Y X R X r X r Y XRXR XrXr XrXr Y copyright cmassengale Genotypes: X R X r, X r Y Genotype Ratio: 1:1 Phenotypes: Red Eyed Female, White Eyed Male Phenotype Ratio: 1:1

70 Female Carriers copyright cmassengale

71 copyright cmassengale Bell Ringer: Monohybrid Cross (B) Brown Eyes = Dominant (b)Blue Eyes = Recessive Genetic Problem: Cross a male who is homozygous for brown eyes with a female who has blue eyes and answer the following questions. 1.What are the Genotype possibilities? 2.What is the Genotype ratio? 3.What are the Phenotype possibilities? 4.What is the Phenotype ratio?