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Why Is He Different from Both Parents?

The Genetics of ABO Blood Types

Co Authors:

Jun Liang
Science Department
Borough of Manhattan Community College / City University of New York

William J. Rice
Simons Electron Microscopy Center
New York Structural Biology Center


This case study was developed to teach the topic of human ABO blood type and genetic inheritance in biology courses at the lower undergraduate level or upper high school level. It is suitable for entry level biology, genetics, and physiology courses. The case narrative tells the story of Kevin, a teenager who is puzzled by the fact that neither of his parents can donate blood to him. He and his best friend ask their biology teacher for help, and she explains human ABO blood types at the molecular and genetic level to solve the mystery. The case consists of three sections, which can be used sequentially or separately. After completing the case study, students will understand the molecular basis of ABO blood types and how genes control the phenotype and genotype of an individual. They will also have a better understanding of how human ABO blood type is inherited from generation to generation.

  • Understand the significance of human ABO blood types.
  • Explain surface markers, genes, and alleles that determine human blood types.
  • Determine the possible genetic makeup of an individual with a given blood type.
  • Use genetic principles to determine possible inheritance of ABO blood type.
  • Understand antigens and antibodies created in each blood group.
  • Explain blood transfusion reactions.
Keywords: carbohydrate; genetic inheritance; ABO blood type; positive; negative; antibody; blood transfusion; blood serum; Punnett square; Mendelian genetics
Topical Area: N/A
Educational Level: High school, Undergraduate lower division
Formats: PDF
Type/Method: Analysis (Issues), Discussion
Language: English
Subject Headings: Biology (General)   Cell Biology   Genetics / Heredity   Physiology   Science (General)  
Date Posted: 7/25/2016
Date Modified: N/A
Copyright: Copyright held by the National Center for Case Study Teaching in Science, University at Buffalo, State University of New York. Please see our usage guidelines, which outline our policy concerning permissible reproduction of this work.

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