Skip to Content

Cystic Fibrosis

Then and Now


Kathleen A. Nolan
Department of Biology, Health Promotion, and Health Care Management
St. Francis College
Allen J. Burdowski
Biology and Health Sciences
St. Francis College


This PowerPoint-driven, flipped case study begins with a short video about a woman suffering from cystic fibrosis (CF) in the 1970s, a friend of the lead author's, whom she met in college and who died in her twenties. Hooked by this personal story, students then delve into the genetics and biology of cystic fibrosis as they learn about the difference between dominant and recessive genes, make Punnett squares that depict various types of inheritance, distinguish between probability and actual numbers, differentiate types of mutations, and learn about the opportunistic infections that CF patients often succumb to.  Students conclude the case by watching two additional videos on chest compression machines and the contemporary life expectancy of patients with CF.  In addition to the scientific content presented in the case, it is hoped that students will empathize with, and be motivated by, the young people presented in the videos as they struggle with a very real, incurable disease deeply rooted in genetics.


  • Distinguish genotype from phenotype of a recessive trait.
  • Distinguish between the different patterns of inheritance of simple (monogenic) traits.
  • Construct Punnett squares to determine the probability of phenotypes for each pattern of inheritance.
  • Outline the procedure for analyzing chromosomes.
  • Describe the relationship between DNA triplet codons and amino acids.
  • Construct and calculate various probabilities of inheriting autosomal recessive and dominant, and sex-linked recessive and dominant traits.
  • Understand the difference between actually getting a disease and the chances for getting a disease.
  • Understand the biology of CF, such as its location (locus) on which chromosome, the role of the normally-functioning cystic fibrosis transmembrane conductance or CFTR protein in the cell, and how its defects (caused by the gene's mutations) contribute to CF.
  • Know the symptoms of CF and the organ systems it affects.
  • Understand that people can die of opportunistic infections related to a defective gene.
  • Know what life expectancy is and how it can change.


cystic fibrosis; cf; genetics; Punnett square; opportunistic infections; life expectancy;

Topical Areas


Educational Level

Undergraduate lower division, Undergraduate upper division


PDF, PowerPoint

Type / Methods

Directed, Discussion, Flipped



Subject Headings

Biology (General)  |   Cell Biology  |   Genetics / Heredity  |  

Date Posted


Teaching Notes

Case teaching notes are password-protected and access to them is limited to paid subscribed instructors. To become a paid subscriber, begin the process by registering.

Teaching notes are intended to help teachers select and adopt a case. They typically include a summary of the case, teaching objectives, information about the intended audience, details about how the case may be taught, and a list of references and resources.

Answer Key

Answer keys for the cases in our collection are password-protected and access to them is limited to paid subscribed instructors. To become a paid subscriber, begin the process by registering.


The following video(s) are recommended for use in association with this case study.

  • Cystic Fibrosis: Then and Now
    This video opens with the personal story of a woman suffering from cystic fibrosis (CF) in the 1970s, a friend of the lead author’s, whom she met in college. The video then relates selected facts and statistics about CF, and ends with a description of current treatments that have helped to extend the life expectancy of those with CF. Running time: 4: 54 min. Created by Kathleen Nolan for the National Center for Case Study Teaching in Science, 2016.
  • Living with Cystic Fibrosis
    This video explains a day in the life of a teenager with cystic fibrosis. The video focuses on the daily regimen of treatments that Holly Rosanna, who is eighteen years old and has the disease, follows, including the use of a mechanized compression vest to break up the mucous in her lungs. Running time: 13:57 min. Created by Holly Rosanna, 2011.
  • My Life Expectancy
    In this video, nineteen-year-old Claire Wineland talks about her life expectancy and the emotional issues of living with CF. Running time: 5:03 min. Created by The Clarity Project, 2015.


Clewert Sylvester
Biology & Health Promotion
Brooklyn, NY
This was very well done.