Chapter 4: Genetic Inheritance

  1. Handout & Exercise:

4.1 Mendelian Genetics: Monohybrid and dihybrid


Reading material:

4.1.1 Monohybrid

  • Describe the characteristics of Mendel's pea plant.
  • Explain the Mendel's experiments on monohybrid cross.
  • State Mendel's first law - Law of Segregation
  • Calculate the genotypic ratio (1:2:1) and phenotypic ratio (3:1) in F2 generation.
  • Calculate the phenotypic ratio of test cross (1:1)
  • Explain the relationship between Mendel's Law of Segregation and Meiosis.

Reading material:

4.1.2 Dihybrid

  • Explain the Mendel's Experiment in dihybrid cross
  • State Mendel's second Law - Law of Independent Assortment
  • Explain the relationship between Mendel's Independent Assortment and meiosis
  • Calculate genotypic ratio and phenotypic ratio (9:3:3:1) up to the F2 generation using Punnett square.
  • Calculate the phenotypic ratio of test cross (1:1:1:1)

Reading material:

4.2 Deviation from Mendelian Inheritance

  • Explain why it is deviate from Mendelian genetics.
  • Types of inheritance deviate from Mendelian Genetic
    1. Codominant alleles
    2. Incomplete dominant alleles
    3. Multiple alleles
    4. Polygenic inheritance
    5. Lethal alleles
    6. Linked genes
    7. Sex-linked genes
    8. Epistasis (for further understanding)
    9. Pleiotropy (for further understanding)

4.2.1 Codominant alleles


4.2.2 Incomplete Dominant alleles


4.2.3 Multiple alleles


4.2.4 Polygenic Inheritance


4.2.5 Lethal alleles


4.2.6 Linked genes

4.2.7 Sex-linked genes



Reading material:

4.3 Genetic Mapping


Reading material: