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Those Old Kentucky Blues

An Interrupted Case Study

Co Authors:

Celeste A. Leander
Department of Biology & Zoology
The University of British Columbia

Robert J. Huskey
Biology Department
University of Virginia


This interrupted case study begins with the construction of a pedigree following an initial encounter with a clan of “blue people.” After constructing a pedigree, students decide whether the condition (methemoglobinemia) is a heritable trait. Students are then exposed to a different perspective of this condition and have to re-evaluate the inheritance pattern. This case study was written for a first year honors course in general biology. It could be modified for most general science majors’ biology, genetics, biochemistry, and cell biology courses.

  • Hypothesis generation.
  • Pedigree construction and analysis.
  • Evaluation of inheritance patterns.
  • Reconciliation of changing inheritance patterns, depending on perspective.
Keywords: Mendelian inheritance patterns; phenotype; incomplete dominance; pedigree; skin color; enzyme; hemoglobin; methemoglobinemia; Kentucky; Appalachian Mountains
Topical Area: Scientific method
Educational Level: High school, Undergraduate lower division
Formats: PDF
Type/Method: Interrupted
Language: English
Subject Headings: Biology (General)   Biochemistry   Cell Biology   Genetics / Heredity  
Date Posted: 3/4/2008
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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