Chapter 11

1. Chapter 11 Introduction to Genetics (no two are the same)

2. Section Outline Section 11-1 A. Gregor Mendel’s Peas B. Genes and Dominance C. Segregation 1. The F1 Cross 2. Explaining the F1 Cross 11–1 The Work of Gregor Mendel

3. Introduction • The branch of science that is concerned with the ways in which inheritable information is transmitted to offspring is known as Genetics

4. Introduction and Reminders • Heredity: traits (characteristics) are passed down from the parent to the offspring. • Sexual Reproduction:the fusion of sex cells • Sex cells (gametes) sperm and ova cells • Chromosomes of each gamete contain the traits of the parent

5. (A) Gregor Mendel • Do now Video: Understanding Genetics 20:24

6. (A) Gregor Mendel • An Austrian monk who performed a series of experiments with sweet peas (1856-1868) • Experimented on pea plants because he Knew: • Peas Self- Pollinated • They have Single parent • Example of Selective (True/pure) Breeding • Fertilization occurred: fusion of sperm and eggs cells • Reproduced in high numbers in a short time

7. (A) Gregor Mendel He wanted to see how these traits were inherited by the offspring plants Mendel proposed that certain traits were inherited as a result of the transmission of hereditary factor Mendel’s hereditary factors, called genes,

8. (A) Gregor Mendel • Two genes (one from each parent) called alleles determine the trait of the offspring Genes are the Chemical factors Example~~ Gene for: Flower Color ~ ~

9. (B) Genes and Dominance He studied Seven traits -Trait: a specific characteristics, ex Height, color, shape -Each trait had two contrasting Characteristics: “Same Gene Different Alleles”

10. B. Genes and Dominance Mendel’s Seven F1 Crosses on Pea Plants What???? Seed Shape Seed Color Seed Coat Color Pod Shape Pod Color Flower Position Plant Height Round Yellow Gray Smooth Green Axial Tall White Constricted Yellow Terminal Short Wrinkled Green Round Yellow Gray Smooth Green Axial Tall

11. B. Genes and Dominance His Hypothesis was something was transmitting information to the offspring

13. B. Genes and Dominance Principles of Dominance Section 11-1 P Generation F1 Generation F2 Generation Tall Short Tall Tall Tall Tall Tall Short

14. B. Genes and Dominance Principles of Dominance Section 11-1 P Generation F1 Generation F2 Generation 100% Tall Short Tall Tall Tall Tall Tall Short

15. B. Genes and Dominance Principles of Dominance Section 11-1 P Generation F1 Generation F2 Generation 75% 25% Tall Short Tall Tall Tall Tall Tall Short P  F1 (100% pure)  F2 (75%, 25%)

16. (B) Genes and Dominance P  F1 (100% pure)  F2 He studied Seven traits his F2 numbers were staggering 787 705 6000 244 277 2000

17. Mendel's Three Major Concepts Law of Dominance Segregation Independent Assortment

18. Principle of Dominance

19. 1. Principle of Dominance

20. 1. Principle of Dominance Also referred to as Law of Dominance • States that the dominant allele will mask (cover) the recessive allele if the pair is hybrid • Tt = tall, since T is dominant for tallness • The only time that the recessive allele is shown is when its homozygous recessive • tt = short

21. Law of Segregation

22. 2. Principle of Segregation • States that the alleles of an allelic pair will separate and then recombine to form a new trait • Ex: Punnet square Tt T t

23. 2. Principle of Segregation Parent 1Parent 2 Separation Recombination Video: Segregation chapter 11d

24. Do Now: • Copy the table below. • In the table Define the words genotype + phenotype (using your homework) • Match the examples below in the appropriate box: Blue eyes, tall, homozygous, hybrid, short, heterozygous

25. Do Now:

26. 2. (RVW). Principle of Segregation Parent 1Parent 2 Separation Recombination Video: Segregation chapter 11d

27. 11–2 Probability and Punnett Squares Section Outline Section 11-2 A. Genetics and Probability B. Punnett Squares C. Probability and Segregation D. Probabilities Predict Averages

28. Tt X Tt Cross Section 11-2

29. Tt X Tt Cross

30. Basic Terms: • Genotype- genetic makeup (is it homozygous or heterozygous) • Homozygous: a.k.a. Pure, Having the same alleles, (BB, bb) • Heterozygous: a.k.a. Hybrid, Having different alleles for a certain trait (Bb) • Phenotype- the PHYSICAL appearance of the offspring due to the genotype

31. Homozygous • Pure • Both alleles are the same • TT = homozygous tall • tt = homozygous short

32. Heterozygous • Also known as Hybrid • Both alleles are different • Tt = heterozygous or hybrid

33. Homozygous Dominant x Homozygous Dominant Round Round 4 round peas

34. Homozygous Dominant x Homozygous Recessive Round Wrinkled

35. Heterozygous Dominant x Heterozygous Dominant Round Round Wrinkled

36. How can we identify this pea’s genotype???? (RR or Rr)

37. Law of Independent Assortment

38. (III) Generations P1 F1  F2 (parents) (offspring) (grandchildren) TT x tt  Tt  TT, Tt, tt

39. (III) Generations

40. In the early 1900’s, T.H. Morgan carried out breeding experiments (crosses) with the fruit fly, Drosophila melanogaster that supported Mendel’s findings

41. Do Now: • Is tongue rolling a dominant or recessive trait???

42. Do Now: • Is tongue rolling a dominant or recessive trait??? • 1` • TT, Tt tt

43. Punnet Square Used to predict possible offspring

44. Background Information • Genes: have alleles (found on chromosomes) • Capital letter = dominance Lower-case letter = recessive Ex: T = tallness which is dominant t = shortness which is recessive

45. T = Tall T T t = short T t t T t T t T t t How many offspring are Tall? How many offspring are short?

46. T = Tall T T t = short T t t T t T t T t t How many offspring are Tall? 4 = Tall How many offspring are short? 0 = short

47. T = Tall T t t = short T T T T t T t t t t How many offspring are Tall? How many offspring are short?

48. T = Tall T t t = short T T T T t T t t t t 3 = Tall How many offspring are Tall? 1 = short How many offspring are short?

49. G = green G G g = yellow G G G G G G g G g g

50. G = green G G g = yellow G G G G G G g G g g Genotype = symbols Phenotype = green