Gen Bio 2 - Mendelian Laws of Inheritance

General Biology

1. General Biology 2 Science, Technology, Engineering, and Mathematics Lesson 1.1 Mendelian Laws of Inheritance

2. 2 What traits run in your family? What did you inherit from your parents? What makes your family distinct from other families?

3. 3 How well do you resemble your siblings? Do you share the same facial features and complexion?

4. 4 Some of you may have inherited a widow’s peak and the ability to roll your tongue from your either or both of your parents, while some of you may lack these genetic traits.

5. 5 Inheritance may also involve more complex traits such as the intelligence quotient level or IQ level. From whom do you think you inherited your natural intelligence?

6. 6 How did the experiments of Gregor Mendel lay the foundation for the study of transmission genetics?

7. 7 Predict genotypes and phenotypes of parents and offspring using the laws of inheritance (STEM_BIO11/12-IIIa-b-1).

8. 8 Explain the foundations and development of Mendelian genetics. Describe and apply the Mendelian laws of inheritance.

9. 9 Introduction to Inheritance Looking at yourself in the mirror...

10. 10 Introduction to Inheritance ...have you ever wondered how you have inherited your biological traits from your parents?

11. 11 Introduction to Inheritance ...have you ever wondered how you have inherited your biological traits from your parents?

12. 12 Introduction to Inheritance Genetics answers most of our inquiries about how traits are transmitted from parents to their children.

13. 13 Introduction to Inheritance Genetics The word GENETIC comes from the Greek word  ” genetikos ”, which comes from the word genesis meaning “ origin “.

14. 14 Introduction to Inheritance Genetics Heredity Variation

15. 15 Introduction to Inheritance Genetics Heredity Variation

16. 16 Introduction to Inheritance Genetics Heredity Variation

17. 17 Introduction to Inheritance Genetics Heredity Variation

18. 18 Introduction to Inheritance Branches of Genetics Molecular genetics Cytogenetics Transmission genetics Population genetics

19. 19 Introduction to Inheritance Branches of Genetics Molecular genetics deals with DNA and gene expression and regulation. Cytogenetics Transmission genetics Population genetics

20. 20 Molecular Genetics

21. 21 Introduction to Inheritance Branches of Genetics Molecular genetics Cytogenetics deals with chromosome structure and behavior during cell division. Transmission genetics Population genetics

22. 22 Cytogenetics

23. 23 Introduction to Inheritance Branches of Genetics Molecular genetics Cytogenetics Transmission genetics deals with different patterns of inheritance. Population genetics

24. 24 Transmission Genetics

25. 25 Introduction to Inheritance Branches of Genetics Molecular genetics Cytogenetics Transmission genetics Population genetics deals with how forces of evolution influence genes in populations.

26. 26 Population Genetics

27. 27 Introduction to Inheritance Transmission genetics, also called classical genetics, is the oldest subdiscipline of genetics. It attempts to predict outcomes of reproduction.

28. 28 Brief Background of Gregor Mendel Farm Tender Beekeeper Academician Augustinian Monk Father of Genetics

29. 29 Brief Background of Gregor Mendel Mendel took the path to priesthood when he entered Augustinian monastery of St. Thomas and became monk. This is also where he performed his pea plant studies .

30. 30 Pea Plant Hybridization Mendel chose the legumes garden peas or Pisum sativum for his hybridization experiments.

31. 31 Pea Plant Hybridization

32. 32 Pea Plant Hybridization What makes peas ideal for genetic studies?

33. 33 Pea Plant Hybridization What makes peas ideal for genetic studies? They exhibit vigorous growth.

34. 34 Pea Plant Hybridization What makes peas ideal for genetic studies? They exhibit vigorous growth. They can self- fertilize.

35. 35 Pea Plant Hybridization What makes peas ideal for genetic studies? They exhibit vigorous growth. They can self- fertilize. They can cross- fertilize.

36. 36

37. 37

38. 38 Challenges faced by Mendel Previous Notions of Inheritance Pangenesis Homunculus theory Blending theory

39. 39 Challenges faced by Mendel Previous Notions of Inheritance Pangenesis Homunculus theory Blending theory

40. 40 Challenges faced by Mendel Previous Notions of Inheritance Pangenesis Homunculus theory Blending theory Pangenesis was the belief that seeds are produced in different organs and will later on gather to form the offspring.

41. 41 Challenges faced by Mendel Previous Notions of Inheritance Pangenesis Homunculus theory Blending theory The invention of the microscope made people believe that sperm cells bear a homunculus or little man.

42. 42 Challenges faced by Mendel Previous Notions of Inheritance Pangenesis Homunculus theory Blending theory The blending theory of inheritance states that traits of parents blend every generation of offspring.

43. 43 Rediscovery of Mendel’s Work Mendel’s paper, The Experiments on Plant Hybridization , was rediscovered independently by de Vries, Correns, and von Tschermak in 1900s. Hugo de Vries (1848–1935) Carl Correns (1864–1933) Erich von Tschermak (1871–1962)

44. 44 What makes Pisum sativum an ideal model organism for genetic studies?

45. Review of Genetic Terminologies A chromosome consists of a DNA molecule, which serve as the repository of genetic information in cells.

46. Review of Genetic Terminologies Our chromosomes occur in pairs called homologous chromosomes .

47. Review of Genetic Terminologies Our chromosomes occur in pairs called homologous chromosomes . Paternal (from the father or male parent)

48. Review of Genetic Terminologies Our chromosomes occur in pairs called homologous chromosomes . Paternal (from the father or male parent) Maternal (from the mother or female parent)

49. Review of Genetic Terminologies A gene is the basic unit of heredity. It controls the expression of a biological characteristic .

50. Review of Genetic Terminologies A gene is the basic unit of heredity. It controls the expression of a biological characteristic . A characteristic is a heritable feature of an organism.

51. Review of Genetic Terminologies In our given example, the gene controls height of peas .

52. Review of Genetic Terminologies Also, note that genes occur in pairs . Thus, a pair of genes control a particular characteristic.

53. Review of Genetic Terminologies How about this gene pair? What does it control?

54. Review of Genetic Terminologies How about this gene pair? What does it control? The highlighted gene controls seed shape in peas.

55. Review of Genetic Terminologies Alleles are the alternative forms of a gene.

56. Review of Genetic Terminologies Genotype refers to the set of alleles possessed by an organism.

57. Review of Genetic Terminologies The genotype is homozygous if the alleles are identical.

58. Review of Genetic Terminologies The genotype is heterozygous if the alleles are different.

59. Review of Genetic Terminologies Let’s say that the given chromosomes give rise to the following observable traits: Tall Round-seeded

60. Review of Genetic Terminologies Let’s say that the given chromosomes give rise to the following observable traits: Tall Round-seeded Phenotypes refer to the actual manifestation of genotypes into observable traits.

61. Review of Genetic Terminologies If the phenotype for seed shape is round , then we can conclude that:

62. Review of Genetic Terminologies If the phenotype for seed shape is round , then we can conclude that: The allele for round pea is the dominant allele . The allele for wrinkled pea is the recessive allele .

63. 63 Pea Plant Characters Gregor Mendel utilized seven characteristics of peas in his hybridization experiments. Each exists in two variants.

64. 64 How are the alleles of a gene transmitted from parents to offspring?

65. 65 Monohybrid Cross A monohybrid cross is a mating between two individuals involving one characteristic or one pair of contrasting traits .

66. 66 Monohybrid Cross In this example, the height of pea is involved.

67. 67 Monohybrid Cross In this example, the height of pea is involved. The parents have contrasting traits (i.e., tall and dwarf).

68. 68 Monohybrid Cross In this example, the height of pea is involved. The parents have contrasting traits (i.e., tall and dwarf). Both parents must also be true-breeding or homozygous.

69. 69 Monohybrid Cross P generation F 1 generation F 2 generation

70. 70 Monohybrid Cross P generation F 1 generation F 2 generation The parental generation consists of the true- breeding initial parents.

71. 71 Monohybrid Cross P generation F 1 generation F 2 generation The first filial generation consists of the offspring of the P generation.

72. 72 Monohybrid Cross P generation F 1 generation F 2 generation The second filial generation consists of the offspring of F 1 gen.

73. 73 Monohybrid Cross Result 1 : The dwarf trait disappeared in the F 1 generation.

74. 74 Monohybrid Cross P generation F 1 generation Result 1 : The dwarf trait disappeared in the F 1 generation.

75. 75 Monohybrid Cross P generation F 1 generation Result 1 : The dwarf trait disappeared in the F 1 generation. Explanation : Tall trait must be dominant over the dwarf trait.

76. 76 Monohybrid Cross In a heterozygous individual, one allele (dominant) completely masks the expression of the other allele (recessive). Principle of Dominance

77. 77 Monohybrid Cross Principle of Dominance If we assign letters to each allele :

78. 78 Monohybrid Cross Principle of Dominance If we assign letters to each allele : T - tall

79. 79 Monohybrid Cross Principle of Dominance If we assign letters to each allele : T - tall t - dwarf

80. 80 Monohybrid Cross Principle of Dominance If we assign letters to each allele : T - tall t - dwarf Thus, we will have the corresponding genotypes and phenotypes :

81. 81 Monohybrid Cross Principle of Dominance If we assign letters to each allele : T - tall t - dwarf Thus, we will have the corresponding genotypes and phenotypes : TT - tall

82. 82 Monohybrid Cross Principle of Dominance If we assign letters to each allele : T - tall t - dwarf Thus, we will have the corresponding genotypes and phenotypes : TT - tall Tt - tall

83. 83 Monohybrid Cross Principle of Dominance If we assign letters to each allele : T - tall t - dwarf Thus, we will have the corresponding genotypes and phenotypes : TT - tall Tt - tall tt - dwarf

84. 84 Monohybrid Cross Thus, we can have the genetic cross as follows:

85. 85 Monohybrid Cross Thus, we can have the genetic cross as follows: P generation Phenotypes Genotypes F 1 generation F 2 generation

86. 86 Monohybrid Cross Thus, we can have the genetic cross as follows: P generation × Tall Dwarf Phenotypes Genotypes F 1 generation F 2 generation

87. 87 Monohybrid Cross Thus, we can have the genetic cross as follows: P generation TT × tt Tall Dwarf × Phenotypes Genotypes F 1 generation F 2 generation

88. 88 Monohybrid Cross Thus, we can have the genetic cross as follows: P generation TT × tt Tall Dwarf × Phenotypes Genotypes F 1 generation F 2 generation Phenotypic Ratio (PR): Genotypic Ratio (GR):

89. 89 Monohybrid Cross Thus, we can have the genetic cross as follows: P generation TT × tt Tall Dwarf × Phenotypes Genotypes F 1 generation 100% or All Tall F 2 generation Phenotypic Ratio (PR): Genotypic Ratio (GR):

90. 90 Monohybrid Cross Thus, we can have the genetic cross as follows: P generation TT × tt Tall Dwarf × Phenotypes Genotypes F 1 generation 100% or All Tall F 2 generation 100% or All Tt Phenotypic Ratio (PR): Genotypic Ratio (GR):

91. 91 Monohybrid Cross Thus, we can have the genetic cross as follows: P generation TT × tt Tall Dwarf × Phenotypes Genotypes F 1 generation 100% or All Tall F 2 generation 3/4 Tall: 1/4 Dwarf 100% or All Tt Phenotypic Ratio (PR): Genotypic Ratio (GR):

92. 92 Monohybrid Cross Thus, we can have the genetic cross as follows: P generation TT × tt Tall Dwarf × Phenotypes Genotypes F 1 generation Phenotypic Ratio (PR): Genotypic Ratio (GR): 100% or All Tall F 2 generation 3/4 Tall: 1/4 Dwarf 100% or All Tt 1/4 TT: 2/4 Tt: 1/4 tt

93. 93 Monohybrid Cross Result 2 : The phenotypes in the F 2 generation occur in a ratio of 3:1.

94. 94 Monohybrid Cross F 1 generation F 2 generation Result 2 : The phenotypes in the F 2 generation occur in a ratio of 3:1.

95. 95 Monohybrid Cross F 1 generation F 2 generation Result 2 : The phenotypes in the F 2 generation occur in a ratio of 3:1.

96. 96 Monohybrid Cross F 1 generation F 2 generation Result 2 : The phenotypes in the F 2 generation occur in a ratio of 3:1. Explanation : The alleles are segregating during gamete formation.

97. 97 Monohybrid Cross The two alleles of a gene in an individual segregate or separate from each other during gamete formation. Law of Segregation

98. 98 Monohybrid Cross Law of Segregation P generation cross F 1 generation cross

99. 99 Monohybrid Cross Law of Segregation TT × tt Tt × Tt P generation cross F 1 generation cross

100. 100 Monohybrid Cross Law of Segregation TT × tt Tt × Tt alleles P generation cross F 1 generation cross

101. 101 Monohybrid Cross Law of Segregation TT × tt T T t t Tt × Tt alleles P generation cross F 1 generation cross

102. 102 Monohybrid Cross Law of Segregation TT × tt T T t t Tt × Tt alleles P generation cross F 1 generation cross progeny

103. 103 Monohybrid Cross Law of Segregation TT × tt T T t t Tt × Tt Tt Tt alleles P generation cross F 1 generation cross progeny

104. 104 Monohybrid Cross Law of Segregation TT × tt T T t t Tt × Tt Tt Tt Tt Tt alleles P generation cross F 1 generation cross progeny

105. 105 Monohybrid Cross Law of Segregation TT × tt T T t t Tt × Tt Tt Tt Tt Tt alleles P generation cross F 1 generation cross progeny

106. 106 Monohybrid Cross Law of Segregation TT × tt T T t t Tt × Tt T t T t Tt Tt Tt Tt alleles P generation cross F 1 generation cross progeny

107. 107 Monohybrid Cross Law of Segregation TT × tt T T t t Tt × Tt T t T t Tt Tt Tt Tt TT Tt alleles P generation cross F 1 generation cross progeny

108. 108 Monohybrid Cross Law of Segregation TT × tt T T t t Tt × Tt T t T t Tt Tt Tt Tt TT Tt Tt tt alleles P generation cross F 1 generation cross progeny

109. 109 Punnett Square Let’s apply Punnett square to our P gen cross . 1. Write the given. 2. Write the genotypes. 3. Identify the alleles. 4. Draw the square. 5. Distribute alleles. 6. Combine alleles. 7. Determine phenotypes. 8. Determine ratios.

110. 110 Punnett Square Let’s apply Punnett square to our P gen cross . 1. Write the given. 2. Write the genotypes. 3. Identify the alleles. 4. Draw the square. 5. Distribute alleles. 6. Combine alleles. 7. Determine phenotypes. 8. Determine ratios. Tall × Dwarf

111. 111 Punnett Square Let’s apply Punnett square to our P gen cross . 1. Write the given. 2. Write the genotypes. 3. Identify the alleles. 4. Draw the square. 5. Distribute alleles. 6. Combine alleles. 7. Determine phenotypes. 8. Determine ratios. Tall × Dwarf TT × tt

112. 112 Punnett Square Let’s apply Punnett square to our P gen cross . 1. Write the given. 2. Write the genotypes. 3. Identify the alleles. 4. Draw the square. 5. Distribute alleles. 6. Combine alleles. 7. Determine phenotypes. 8. Determine ratios. Tall × Dwarf TT × tt T T t t

113. 113 Punnett Square Let’s apply Punnett square to our P gen cross . 1. Write the given. 2. Write the genotypes. 3. Identify the alleles. 4. Draw the square. 5. Distribute alleles. 6. Combine alleles. 7. Determine phenotypes. 8. Determine ratios. Tall × Dwarf TT × tt T T t t

114. 114 Punnett Square Let’s apply Punnett square to our P gen cross . 1. Write the given. 2. Write the genotypes. 3. Identify the gametes. 4. Draw the square. 5. Distribute gametes. 6. Combine gametes. 7. Determine phenotypes. 8. Determine ratios. Tall × Dwarf TT × tt T T t t T T t t

115. 115 Punnett Square Let’s apply Punnett square to our P gen cross . Tt Tt Tt Tt 1. Write the given. 2. Write the genotypes. 3. Identify the alleles. 4. Draw the square. 5. Distribute alleles. 6. Combine alleles. 7. Determine phenotypes. 8. Determine ratios. Tall × Dwarf TT × tt T T t t T T t t

116. 116 Punnett Square Let’s apply Punnett square to our P gen cross . Tt (Tall) Tt (Tall) Tt (Tall) Tt (Tall) 1. Write the given. 2. Write the genotypes. 3. Identify the alleles. 4. Draw the square. 5. Distribute alleles. 6. Combine alleles. 7. Determine phenotypes. 8. Determine ratios. Tall × Dwarf TT × tt T T t t T T t t

117. 117 Punnett Square Let’s apply Punnett square to our P gen cross . Tt (Tall) Tt (Tall) Tt (Tall) Tt (Tall) 1. Write the given. 2. Write the genotypes. 3. Identify the alleles. 4. Draw the square. 5. Distribute alleles. 6. Combine alleles. 7. Determine phenotypes. 8. Determine ratios. Tall × Dwarf TT × tt T T t t T T t t GR: 100% Tt PR: 100% Tall

118. 118 Punnett Square Let’s apply Punnett square to our F 1 gen cross . 1. Write the given. 2. Write the genotypes. 3. Identify the alleles. 4. Draw the square. 5. Distribute alleles. 6. Combine alleles. 7. Determine phenotypes. 8. Determine ratios.

119. 119 Punnett Square Let’s apply Punnett square to our F 1 gen cross . 1. Write the given. 2. Write the genotypes. 3. Identify the alleles. 4. Draw the square. 5. Distribute alleles. 6. Combine alleles. 7. Determine phenotypes. 8. Determine ratios. Tall × Tall

120. 120 Punnett Square Let’s apply Punnett square to our F 1 gen cross . 1. Write the given. 2. Write the genotypes. 3. Identify the alleles. 4. Draw the square. 5. Distribute alleles. 6. Combine alleles. 7. Determine phenotypes. 8. Determine ratios. Tall × Tall Tt × Tt

121. 121 Punnett Square Let’s apply Punnett square to our F 1 gen cross . 1. Write the given. 2. Write the genotypes. 3. Identify the alleles. 4. Draw the square. 5. Distribute alleles. 6. Combine alleles. 7. Determine phenotypes. 8. Determine ratios. Tall × Tall Tt × Tt T t T t

122. 122 Punnett Square Let’s apply Punnett square to our F 1 gen cross . 1. Write the given. 2. Write the genotypes. 3. Identify the alleles. 4. Draw the square. 5. Distribute alleles. 6. Combine alleles. 7. Determine phenotypes. 8. Determine ratios. Tall × Tall Tt × Tt T t T t

123. 123 Punnett Square Let’s apply Punnett square to our F 1 gen cross . 1. Write the given. 2. Write the genotypes. 3. Identify the alleles. 4. Draw the square. 5. Distribute alleles. 6. Combine alleles. 7. Determine phenotypes. 8. Determine ratios. Tall × Tall Tt × Tt T t T t T t T t

124. 124 Punnett Square Let’s apply Punnett square to our F 1 gen cross . TT Tt Tt tt 1. Write the given. 2. Write the genotypes. 3. Identify the alleles. 4. Draw the square. 5. Distribute alleles. 6. Combine alleles. 7. Determine phenotypes. 8. Determine ratios. Tall × Tall Tt × Tt T t T t T t T t

125. 125 Punnett Square Let’s apply Punnett square to our F 1 gen cross . TT (Tall) Tt (Tall) Tt (Tall) tt (Dwarf) 1. Write the given. 2. Write the genotypes. 3. Identify the alleles. 4. Draw the square. 5. Distribute alleles. 6. Combine alleles. 7. Determine phenotypes. 8. Determine ratios. Tall × Tall Tt × Tt T t T t T t T t

126. 126 Punnett Square Let’s apply Punnett square to our F 1 gen cross . 1. Write the given. 2. Write the genotypes. 3. Identify the alleles. 4. Draw the square. 5. Distribute alleles. 6. Combine alleles. 7. Determine phenotypes. 8. Determine ratios. Tall × Tall Tt × Tt T t T t T t T t GR: 1/4 TT: 2/4 Tt: 1/4 tt PR: 3/4 Tall: 1/4 Dwarf TT (Tall) Tt (Tall) Tt (Tall) tt (Dwarf)

127. 127 Dihybrid Cross A dihybrid cross is a mating between two individuals involving two characteristics or two pairs of contrasting traits .

128. 128 Dihybrid Cross

129. 129 Dihybrid Cross In this example, the seed shape and seed color are involved.

130. 130 Dihybrid Cross In this example, the seed shape and seed color are involved. Two pairs of contrasting traits are involved: round/wrinkled and yellow/green.

131. 131 Dihybrid Cross In this example, the seed shape and seed color are involved. Two pairs of contrasting traits are involved: round/wrinkled and yellow/green. Both parents must also be true-breeding or homozygous.

132. 132 Dihybrid Cross In this example, the seed shape and seed color are involved. Two pairs of contrasting traits are involved: round/wrinkled and yellow/green. Both parents must also be true-breeding or homozygous. All of the offspring in F 1 have round and yellow seeds due to dominance.

133. 133 Punnett Square Let’s apply Punnett square to our P gen cross . 1. Write the given. 2. Assign alleles. 3. Write genotypes. 4. Identify the alleles. 5. Draw the square. 6. Combine alleles . 7. Determine phenotypes. 8. Determine ratios.

134. 134 Punnett Square Let’s apply Punnett square to our P gen cross . 1. Write the given. 2. Assign alleles. 3. Write genotypes. 4. Identify the alleles . 5. Draw the square. 6. Combine alleles . 7. Determine phenotypes. 8. Determine ratios. Round, yellow × Wrinkled, green

135. 135 Punnett Square Let’s apply Punnett square to our P gen cross . 1. Write the given. 2. Assign alleles. 3. Write genotypes. 4. Identify the alleles . 5. Draw the square. 6. Combine alleles . 7. Determine phenotypes. 8. Determine ratios. Round, yellow × Wrinkled, green

136. 136 Punnett Square Let’s apply Punnett square to our P gen cross . 1. Write the given. 2. Assign alleles. 3. Write genotypes. 4. Identify the alleles . 5. Draw the square. 6. Combine alleles . 7. Determine phenotypes. 8. Determine ratios. Round, yellow × Wrinkled, green Seed shape: Round seed is dominant over wrinkled seed .

137. 137 Punnett Square Let’s apply Punnett square to our P gen cross . 1. Write the given. 2. Assign alleles. 3. Write genotypes. 4. Identify the alleles . 5. Draw the square. 6. Combine alleles . 7. Determine phenotypes. 8. Determine ratios. Round, yellow × Wrinkled, green Seed shape: Round seed is dominant over wrinkled seed . R - round r - wrinkled

138. 138 Punnett Square Let’s apply Punnett square to our P gen cross . Round, yellow × Wrinkled, green Seed shape: Round seed is dominant over wrinkled seed . R - round r - wrinkled Seed color: Yellow seed is dominant over green seed . 1. Write the given. 2. Assign alleles. 3. Write genotypes. 4. Identify the alleles . 5. Draw the square. 6. Combine alleles . 7. Determine phenotypes. 8. Determine ratios.

139. 139 Punnett Square Let’s apply Punnett square to our P gen cross . Round, yellow × Wrinkled, green Seed shape: Round seed is dominant over wrinkled seed . R - round r - wrinkled Seed color: Yellow seed is dominant over green seed . Y - yellow y - green 1. Write the given. 2. Assign alleles. 3. Write genotypes. 4. Identify the alleles . 5. Draw the square. 6. Combine alleles . 7. Determine phenotypes. 8. Determine ratios.

140. 140 Punnett Square Let’s apply Punnett square to our P gen cross . Round, yellow × Wrinkled, green Seed shape: Round seed is dominant over wrinkled seed . R - round r - wrinkled Seed color: Yellow seed is dominant over green seed . Y - yellow y - green 1. Write the given. 2. Assign alleles. 3. Write genotypes. 4. Identify the alleles . 5. Draw the square. 6. Combine alleles . 7. Determine phenotypes. 8. Determine ratios.

141. Punnett Square Let’s apply Punnett square to our P gen cross . 1. Write the given. 2. Assign alleles. 3. Write genotypes. 4. Identify the alleles . 5. Draw the square. 6. Combine alleles . 7. Determine phenotypes. 8. Determine ratios. Round, yellow × Wrinkled, green RRYY rryy ×

142. Punnett Square Let’s apply Punnett square to our P gen cross . 1. Write the given. 2. Assign alleles. 3. Write genotypes. 4. Identify the alleles . 5. Draw the square. 6. Combine alleles . 7. Determine phenotypes. 8. Determine ratios. Round, yellow × Wrinkled, green RRYY rryy × RY ry

143. Punnett Square Let’s apply Punnett square to our P gen cross . 1. Write the given. 2. Assign alleles. 3. Write genotypes. 4. Identify the gametes. 5. Draw the square. 6. Combine alleles . 7. Determine phenotypes. 8. Determine ratios. Round, yellow × Wrinkled, green RRYY rryy × RY ry RY RY ry ry

144. Punnett Square Let’s apply Punnett square to our P gen cross . 1. Write the given. 2. Assign alleles. 3. Write genotypes. 4. Identify the alleles . 5. Draw the square. 6. Combine alleles . 7. Determine phenotypes. 8. Determine ratios. Round, yellow × Wrinkled, green RRYY rryy × RY ry RrYy RrYy RrYy RrYy RY RY ry ry

145. Punnett Square Let’s apply Punnett square to our P gen cross . 1. Write the given. 2. Assign alleles. 3. Write genotypes. 4. Identify the alleles . 5. Draw the square. 6. Combine alleles . 7. Determine phenotypes. 8. Determine ratios. Round, yellow × Wrinkled, green RRYY rryy × RY ry RrYy (round, yellow) RrYy (round, yellow) RrYy (round, yellow) RrYy (round, yellow) RY RY ry ry

146. Punnett Square Let’s apply Punnett square to our P gen cross . 1. Write the given. 2. Assign alleles. 3. Write genotypes. 4. Identify the alleles . 5. Draw the square. 6. Combine alleles . 7. Determine phenotypes. 8. Determine ratios. Round, yellow × Wrinkled, green RRYY rryy × RY ry RrYy (round, yellow) RrYy (round, yellow) RrYy (round, yellow) RrYy (round, yellow) RY RY ry ry GR: 100% RrYy PR: 100% round, yellow

147. Punnett Square Let’s apply Punnett square to our F 1 gen cross . 1. Write the given. 2. Write genotypes. 3. Identify the alleles . 4. Draw the square. 5. Distribute the alleles . 6. Combine alleles . 7. Determine phenotypes. 8. Determine ratios.

148. Punnett Square Let’s apply Punnett square to our F 1 gen cross . 1. Write the given. 2. Write genotypes. 3. Identify the alleles . 4. Draw the square. 5. Distribute the alleles . 6. Combine alleles . 7. Determine phenotypes. 8. Determine ratios. Round, yellow × Round, yellow

149. Punnett Square Let’s apply Punnett square to our F 1 gen cross . 1. Write the given. 2. Write genotypes. 3. Identify the alleles . 4. Draw the square. 5. Distribute the alleles . 6. Combine alleles . 7. Determine phenotypes. 8. Determine ratios. Round, yellow × Round, yellow RrYy RrYy ×

150. Punnett Square Let’s apply Punnett square to our F 1 gen cross . 1. Write the given. 2. Write genotypes. 3. Identify the alleles . 4. Draw the square. 5. Distribute the alleles . 6. Combine alleles . 7. Determine phenotypes. 8. Determine ratios. Round, yellow × Round, yellow RrYy RrYy × TIP: Use the branching technique.

151. Punnett Square Let’s apply Punnett square to our F 1 gen cross . 1. Write the given. 2. Write genotypes. 3. Identify the alleles . 4. Draw the square. 5. Distribute the alleles . 6. Combine alleles . 7. Determine phenotypes. 8. Determine ratios. Round, yellow × Round, yellow RrYy RrYy × TIP: Use the branching technique. Rr R Yy r

152. Punnett Square Let’s apply Punnett square to our F 1 gen cross . 1. Write the given. 2. Write genotypes. 3. Identify the alleles . 4. Draw the square. 5. Distribute the alleles . 6. Combine alleles . 7. Determine phenotypes. 8. Determine ratios. Round, yellow × Round, yellow RrYy RrYy × TIP: Use the branching technique. Rr R Yy r Y y Y y

153. Punnett Square Let’s apply Punnett square to our F 1 gen cross . 1. Write the given. 2. Write genotypes. 3. Identify the alleles . 4. Draw the square. 5. Distribute the alleles . 6. Combine alleles . 7. Determine phenotypes. 8. Determine ratios. Round, yellow × Round, yellow RrYy RrYy × TIP: Use the branching technique. Rr R Yy r Y y Y y

154. Punnett Square Let’s apply Punnett square to our F 1 gen cross . 1. Write the given. 2. Write genotypes. 3. Identify the alleles . 4. Draw the square. 5. Distribute the alleles . 6. Combine alleles . 7. Determine phenotypes. 8. Determine ratios. Round, yellow × Round, yellow RrYy RrYy × TIP: Use the branching technique. Rr R Yy r Y y Y y RY Ry rY ry

155. Punnett Square Let’s apply Punnett square to our F 1 gen cross . 1. Write the given. 2. Write genotypes. 3. Identify the alleles . 4. Draw the square. 5. Distribute the alleles . 6. Combine alleles . 7. Determine phenotypes. 8. Determine ratios. Round, yellow × Round, yellow RrYy RrYy × TIP: Use the branching technique. Rr R Yy r Y y Y y RY Ry rY ry Thus, the genotype RrYy has four possible gametes.

156. Punnett Square RrYy RrYy × 1. Write the given. 2. Write genotypes. 3. Identify the alleles . 4. Draw the square. 5. Distribute the alleles . 6. Combine alleles . 7. Determine phenotypes. 8. Determine ratios.

157. Punnett Square RrYy RrYy × RY Ry rY ry RY Ry rY ry 1. Write the given. 2. Write genotypes. 3. Identify the alleles . 4. Draw the square. 5. Distribute the alleles . 6. Combine alleles . 7. Determine phenotypes. 8. Determine ratios.

158. Punnett Square RrYy RrYy × RRYY RRYy RrYY RrYy RRYy RRyy RrYy Rryy RrYY RrYy rrYY rrYy RrYy Rryy rrYy rryy RY Ry rY ry RY Ry rY ry 1. Write the given. 2. Write genotypes. 3. Identify the alleles . 4. Draw the square. 5. Distribute the alleles . 6. Combine alleles . 7. Determine phenotypes. 8. Determine ratios.

159. Punnett Square RrYy RrYy × RRYY round, yellow RRYy round, yellow RrYY round, yellow RrYy round, yellow RRYy round, yellow RRyy round, green RrYy round, yellow Rryy round, green RrYY round, yellow RrYy round, yellow rrYY wrinkled yellow rrYy wrinkled yellow RrYy round, yellow Rryy round, green rrYy wrinkled yellow rryy wrinkled, green RY Ry rY ry RY Ry rY ry 1. Write the given. 2. Write genotypes. 3. Identify the alleles . 4. Draw the square. 5. Distribute the alleles . 6. Combine alleles . 7. Determine phenotypes. 8. Determine ratios.

160. Punnett Square RrYy RrYy × RRYY round, yellow RRYy round, yellow RrYY round, yellow RrYy round, yellow RRYy round, yellow RRyy round, green RrYy round, yellow Rryy round, green RrYY round, yellow RrYy round, yellow rrYY wrinkled yellow rrYy wrinkled yellow RrYy round, yellow Rryy round, green rrYy wrinkled yellow rryy wrinkled, green RY Ry rY ry RY Ry rY ry 1. Write the given. 2. Write genotypes. 3. Identify the alleles . 4. Draw the square. 5. Distribute the alleles . 6. Combine alleles . 7. Determine phenotypes. 8. Determine ratios.

161. Punnett Square RrYy RrYy × 1/16 RRYY 2/16 RrYY 1/16 rrYY 2/16 RRYy 4/16 RrYy 2/16 rrYy 1/16 RRyy 2/16 Rryy 1/16 rryy 9/16 round, yellow 3/16 wrinkled, yellow 3/16 round, green 1/16 wrinkled, green Genotypic Ratio: Phenotypic Ratio: 1. Write the given. 2. Write genotypes. 3. Identify the alleles . 4. Draw the square. 5. Distribute the alleles . 6. Combine alleles . 7. Determine phenotypes. 8. Determine ratios.

162. 162 Dihybrid Cross Result 2 : The phenotypes in the F 2 generation occur in a ratio of 9:3:3:1

163. 163 Dihybrid Cross Result 2 : The phenotypes in the F 2 generation occur in a ratio of 9:3:3:1

164. 164 Dihybrid Cross Result 2 : The phenotypes in the F 2 generation occur in a ratio of 9:3:3:1 Explanation : The genes for seed shape and color are independently assorting.

165. 165 Dihybrid Cross The alleles from different genes are sorted into the gametes independently of each other. Thus, the inheritance of these two genes become independent. Law of Independent Assortment

166. 166 Is the law of segregation still applicable when two genes are already involved? Why do you think so?

167. 167 Laws of Inheritance and Gametogenesis Both laws of inheritance operate during the Anaphase I of meiosis during gamete formation.

168. 168 How is the separation of homologous chromosomes relevant to the laws of inheritance?

169. 169 Brylle is fond of growing crops in his garden. One of the crops that he cultivates is the garden pea ( Pisum sativum ). One strain of his pea plants is heterozygous for flower colors, with genotype Mm. Another strain of his peas has smooth pods and axial flowers with genotype AaBB. What are the alleles produced by each of these two plants with respect to the indicated characteristics?

170. 170 Brylle is fond of growing crops in his garden. One of the crops that he cultivates is the garden pea ( Pisum sativum ). One strain of his pea plants is heterozygous for flower colors, with genotype Mm. Another strain of his peas has smooth pods and axial flowers with genotype AaBB. What are the alleles produced by each of these two plants with respect to the indicated characteristics? Plant 1 (Mm) produces gametes with alleles M and m , while Plant 2 (AaBB) produces gametes with allele combinations AB and aB.

171. 171 171 Nickson cultivated two different plants. The first plant is recessive for trait A, while the second plant is homozygous dominant for trait B and heterozygous for trait C. What are the allele combinations that can be produced by his first and second plants?

172. 172 In pea plants, axial inflorescence is dominant over terminal inflorescence. If Laiza crossed a parent plant that is heterozygous for inflorescence to another plant with terminal inflorescence, what are the genotypic and phenotypic ratios of the offspring?

173. 173 In pea plants, axial inflorescence is dominant over terminal inflorescence. If Laiza crossed a parent plant that is heterozygous for inflorescence to another plant with terminal inflorescence, what are the genotypic and phenotypic ratios of the offspring? The genotypic ratio of the cross is 1/2 AA: 1/2 aa . The phenotypic ratio is 1/2 axial: 1/2 terminal .

174. 174 174 If a parent pea plant that is hybrid for flower color is crossed with a plant that is true-breeding for violet flowers, what are the genotypic and phenotypic ratios of the F 1 generation? Note that having violet flowers is dominant over having white flowers.

175. 175 In pea plants, round seeds are dominant over wrinkled seeds, while the tall trait is dominant over the dwarf trait. If you cross two plants that are both heterozygous for seed shape but homozygous dominant for height, what are the expected genotypic and phenotypic ratios of the offspring?

176. 176 In pea plants, round seeds are dominant over wrinkled seeds, while the tall trait is dominant over the dwarf trait. If you cross two plants that are both heterozygous for seed shape but homozygous dominant for height, what are the expected genotypic and phenotypic ratios of the offspring? The genotypic ratio of the offspring of the cross is 1/4 AABB: 2/4 AaBB: 1/4 aaBB. The phenotypic ratio is 3/4 round tall: 1/4 wrinkled tall.

177. 177 177 Gene A codes for seed color, where having yellow seed is dominant over having a green seed. Gene B codes for pod shape, where the smooth pod is dominant over the constricted pod. Given the cross AaBB × AABb, what is the genotypic and phenotypic ratio of the offspring?

178. 178 Determine the accuracy of each of the following statements. Write true if the statement is correct and false if otherwise. If the genes for seed shape and height of peas are independently assorting, then they highly influence the inheritance of each other. The F 2 generation is the offspring of the P generation. Both the laws of inheritance operate during the first anaphase of meiosis.

179. 179 Provide what is asked in each of the following items. What are the alleles produced by an individual with genotype NN? What are the alleles produced by an individual with genotype Bb? What are the alleles produced by an individual with genotype Mmnn?

180. 180 Genetics is the study of inheritance and variation in organisms. It has various subdisciplines. Transmission genetics is the one that is particularly concerned about the mechanisms or patterns of inheritance.

181. 181 Gregor Mendel is the father of genetics. He performed experiments on garden pea or Pisum sativum . This led him to formulate the laws of inheritance in his publication, Experiments on Plant Hybrids.

182. 182 Different genes control the expression of the characteristics of organisms. Each gene exists in alternative forms called alleles . In terms of expression, genes can either be dominant or recessive. According to the principle of dominance of Mendel, in a heterozygous individual, the dominant allele tends to mask the expression of the recessive allele.

183. 183 Mendel’s monohybrid cross reveals the law of segregation. According to this law, the alleles segregate during gametogenesis. This explains the characteristic 3:1 phenotypic ratio of F 2 in monohybrid crosses.

184. 184 Mendel’s dihybrid cross reveals the law of independent assortment . According to this law, allele pairs from different genes separate independently during gamete formation. This explains the characteristics ratio of 9:3:3:1 of F 2 of dihybrid crosses.

185. 185 Transmission genetics serves as the pioneer field in genetics.

186. 186 186 You crossed two true-breeding lines of violet-flowered and white-flowered peas. Is it possible to establish a true-breeding line of the genotype found in the offspring of your cross? Why or why not?

187. 187

188. Woman with widow's peak , cropped by Kdhondt is licensed under CC BY-SA 4.0 via Wikimedia Commons .