Gregor Mendel conducted experiments with pea plants to study inheritance of traits from one generation to the next. He found that some traits are dominant over recessive traits, and his experiments with cross-pollinating pea plants of different heights showed that the second filial generation exhibited a 3:1 ratio of tall to short plants, demonstrating that height is inherited in a predictable, particulate manner. Mendel's discoveries formed the foundation of classical genetics.

2. Gregor Mendel
The Father of Genetics

3. How are traits passed from one
generation to the next?
Is there a pattern?
Gregor Mendel
The Father of Genetics

4. Parts of a Flower

5. Parts of a Flower - Male
Pollen
(sperm)
Stamen

6. Parts of a Flower - Female Pistil
Egg

7. Pollination Pistil
Pollen
(sperm)
Stamen
Egg

8. Pollination Pistil
Pollen
(sperm)
Stamen
Egg

9. Pollination Pistil
Pollen
(sperm)
Stamen
Egg

10. Fertilization
Egg and sperm join and a
new organism grows

11. Fertilization
Peas form in the pod

12. Life Cycle
of a Pea Plant

13. Life Cycle
of a Pea Plant

14. Life Cycle
of a Pea Plant

15. Life Cycle
of a Pea Plant

16. Life Cycle
of a Pea Plant

17. Life Cycle
of a Pea Plant

18. Life Cycle
of a Pea Plant

19. Life Cycle
of a Pea Plant

20. Life Cycle
of a Pea Plant

21. Why do you think,
bees are excellent pollinators?

22. Why do you think,
How else is pollen transferred
from the stamen to the pistil?
bees are excellent pollinators?

23. Why do you think,
How else is pollen transferred
from the stamen to the pistil?
bees are excellent pollinators?

24. Why do you think,
How else is pollen transferred
from the stamen to the pistil?
bees are excellent pollinators?

25. Self-pollination
PLANT 1

26. Self-pollination
Pollen
(sperm)
Stamen
PLANT 1

27. Self-pollination
Pistil
PLANT 1

28. Self-pollination
Sperm from pollen
fertilizes the egg
PLANT 1

29. Cross-pollination
PLANT 1 PLANT 2

30. Cross-pollination
Pollen
(sperm)
Stamen
PLANT 1 PLANT 2

31. Cross-pollination
Pistil
PLANT 1 PLANT 2

32. Cross-pollination
Plant 1 pollen
fertilizes the egg
of Plant 2
PLANT 1 PLANT 2

33. How do you think Mendel
cross-pollinated pea plants?
Gregor Mendel
The Father of Genetics

34. How do you think Mendel
cross-pollinated pea plants?
How did he prevent
self-pollination?
Gregor Mendel
The Father of Genetics

35. Mendel’s Method

36. Mendel’s Method

37. Mendel’s Method

38. Mendel’s Method

39. Mendel’s Method

40. Mendel’s Method

41. What happens when a short
pea plant cross-pollinates
with a short pea plant?
Gregor Mendel
The Father of Genetics

42. SHORT x SHORT

43. SHORT x SHORT

44. SHORT x SHORT

45. SHORT x SHORT
100% SHORT

46. What happens when a tall pea plant
cross-pollinates with a tall pea plant?
Gregor Mendel
The Father of Genetics

47. TALL x TALL

48. TALL x TALL

49. TALL x TALL

50. TALL x TALL

51. TALL x TALL
100% TALL

52. TALL x TALL TALL x TALL
100% TALL

53. TALL x TALL TALL x TALL
100% TALL

54. TALL x TALL TALL x TALL
100% TALL

55. TALL x TALL TALL x TALL
100% TALL

56. TALL x TALL TALL x TALL
100% TALL 75% TALL, 25% SHORT

57. TALL x TALL TALL x TALL
100% TALL 75% TALL, 25% SHORT

58. P Generation
(parental generation)

59. P Generation
(parental generation)

60. P Generation
(parental generation)

61. P Generation
(parental generation)

62. P Generation
(parental generation)
F1 Generation
(first filial)
100% TALL

63. P Generation
(parental generation)
F1 Generation
(first filial)
100% TALL

64. P Generation
(parental generation)
F1 Generation
(first filial)
100% TALL

65. P Generation
(parental generation)
F1 Generation
(first filial)
100% TALL

66. P Generation
(parental generation)
F1 Generation
(first filial)
100% TALL

67. P Generation
(parental generation)
F1 Generation
(first filial)
100% TALL

68. P Generation
(parental generation)
F1 Generation
(first filial)
100% TALL
F2 Generation
(second filial)
75% TALL, 25% SHORT

69. PUREBRED TALL P Generation
x PUREBRED SHORT (parental generation)
TALL | TALL Short | Short
F1 Generation
(first filial)
100% TALL
F2 Generation
(second filial)
75% TALL, 25% SHORT

70. PUREBRED TALL P Generation
x PUREBRED SHORT (parental generation)
TALL | TALL Short | Short
F1 Generation
(first filial)
100% TALL
TALL | Short TALL | Short TALL | Short TALL | Short
F2 Generation
(second filial)
75% TALL, 25% SHORT

71. PUREBRED TALL P Generation
x PUREBRED SHORT (parental generation)
TALL | TALL Short | Short
F1 Generation
(first filial)
100% TALL
DOMINANT TRAIT = TALL | Short TALL | Short TALL | Short TALL | Short
F2 Generation
(second filial)
75% TALL, 25% SHORT

72. PUREBRED TALL P Generation
x PUREBRED SHORT (parental generation)
TALL | TALL Short | Short
F1 Generation
(first filial)
100% TALL
DOMINANT TRAIT = TALL | Short TALL | Short TALL | Short TALL | Short = RECESSIVE TRAIT
F2 Generation
(second filial)
75% TALL, 25% SHORT

73. PUREBRED TALL P Generation
x PUREBRED SHORT (parental generation)
TALL | TALL Short | Short
F1 Generation
(first filial)
HYBRID TALL
x HYBRID TALL 100% TALL
TALL | Short TALL | Short TALL | Short TALL | Short
F2 Generation
(second filial)
75% TALL, 25% SHORT

74. PUREBRED TALL P Generation
x PUREBRED SHORT (parental generation)
TALL | TALL Short | Short
F1 Generation
(first filial)
HYBRID TALL
x HYBRID TALL 100% TALL
TALL | Short TALL | Short TALL | Short TALL | Short
F2 Generation
(second filial)
75% TALL, 25% SHORT
TALL | TALL TALL | Short TALL | Short Short | Short

75. DOMINANT TRAIT = TALL = T
RECESSIVE TRAIT = Short = t
P Generation
(parental generation)
TALL | TALL Short | Short
F1 Generation
(first filial)
PUNNETT
SQUARE
F2 Generation
(second filial)

76. DOMINANT TRAIT = TALL = T
RECESSIVE TRAIT = Short = t
P Generation
(parental generation)
TALL | TALL Short | Short
T
F1 Generation
(first filial)
T
PUNNETT
SQUARE
F2 Generation
(second filial)

77. DOMINANT TRAIT = TALL = T
RECESSIVE TRAIT = Short = t
P Generation
(parental generation)
TALL | TALL Short | Short
t t
T
F1 Generation
(first filial)
T
PUNNETT
SQUARE
F2 Generation
(second filial)

78. DOMINANT TRAIT = TALL = T
RECESSIVE TRAIT = Short = t
P Generation
(parental generation)
TALL | TALL Short | Short
t t
T Tt
= F1 Generation
(first filial)
T
PUNNETT
SQUARE
TALL | Short
F2 Generation
(second filial)

79. DOMINANT TRAIT = TALL = T
RECESSIVE TRAIT = Short = t
P Generation
(parental generation)
TALL | TALL Short | Short
t t
T Tt Tt
= F1 Generation
(first filial)
T
PUNNETT
SQUARE
TALL | Short TALL | Short
F2 Generation
(second filial)

80. DOMINANT TRAIT = TALL = T
RECESSIVE TRAIT = Short = t
P Generation
(parental generation)
TALL | TALL Short | Short
t t
T Tt Tt
= F1 Generation
(first filial)
T Tt
PUNNETT
SQUARE
TALL | Short TALL | Short TALL | Short
F2 Generation
(second filial)

81. DOMINANT TRAIT = TALL = T
RECESSIVE TRAIT = Short = t
P Generation
(parental generation)
TALL | TALL Short | Short
t t
T Tt Tt
= F1 Generation
(first filial)
T Tt Tt
100% TALL
PUNNETT
SQUARE
TALL | Short TALL | Short TALL | Short TALL | Short
F2 Generation
(second filial)

82. DOMINANT TRAIT = TALL = T
RECESSIVE TRAIT = Short = t
P Generation
(parental generation)
TALL | TALL Short | Short
F1 Generation
(first filial)
TALL | Short TALL | Short TALL | Short TALL | Short
F2 Generation
(second filial)
PUNNETT
SQUARE

83. DOMINANT TRAIT = TALL = T
RECESSIVE TRAIT = Short = t
P Generation
(parental generation)
TALL | TALL Short | Short
F1 Generation
(first filial)
TALL | Short TALL | Short TALL | Short TALL | Short
T
F2 Generation
(second filial)
t
PUNNETT
SQUARE

84. DOMINANT TRAIT = TALL = T
RECESSIVE TRAIT = Short = t
P Generation
(parental generation)
TALL | TALL Short | Short
F1 Generation
(first filial)
TALL | Short TALL | Short TALL | Short TALL | Short
T t
T
F2 Generation
(second filial)
t
PUNNETT
SQUARE

85. DOMINANT TRAIT = TALL = T
RECESSIVE TRAIT = Short = t
P Generation
(parental generation)
TALL | TALL Short | Short
F1 Generation
(first filial)
TALL | Short TALL | Short TALL | Short TALL | Short
T t
T TT
F2 Generation
= (second filial)
t
PUNNETT
SQUARE
TALL | TALL

86. DOMINANT TRAIT = TALL = T
RECESSIVE TRAIT = Short = t
P Generation
(parental generation)
TALL | TALL Short | Short
F1 Generation
(first filial)
TALL | Short TALL | Short TALL | Short TALL | Short
T t
T TT Tt
F2 Generation
= (second filial)
t
PUNNETT
SQUARE
TALL | TALL TALL | Short

87. DOMINANT TRAIT = TALL = T
RECESSIVE TRAIT = Short = t
P Generation
(parental generation)
TALL | TALL Short | Short
F1 Generation
(first filial)
TALL | Short TALL | Short TALL | Short TALL | Short
T t
T TT Tt
F2 Generation
= (second filial)
t tT
PUNNETT
SQUARE
TALL | TALL TALL | Short TALL | Short

88. DOMINANT TRAIT = TALL = T
RECESSIVE TRAIT = Short = t
P Generation
(parental generation)
TALL | TALL Short | Short
F1 Generation
(first filial)
TALL | Short TALL | Short TALL | Short TALL | Short
T t
T TT Tt
F2 Generation
= (second filial)
t Tt
PUNNETT
SQUARE
TALL | TALL TALL | Short TALL | Short

89. DOMINANT TRAIT = TALL = T
RECESSIVE TRAIT = Short = t
P Generation
(parental generation)
TALL | TALL Short | Short
F1 Generation
(first filial)
TALL | Short TALL | Short TALL | Short TALL | Short
T t
T TT Tt
F2 Generation
= (second filial)
t Tt tt
75% TALL, 25% SHORT
PUNNETT
SQUARE
TALL | TALL TALL | Short TALL | Short Short | Short

90. T = Yellow t = Green

91. T = Yellow t = Green