Vol. 7, No. 9: May 15, 2001
Enhancing case-based learning in biology education through computer simulation and Internet conferencing
Mark Bergland, Karen Klyczek, Kim Mogen, and Douglas Johnson,
Department of Biology,
Mary Lundeberg, Department of Teacher Education, and
Marlys A. Nelson, Information Technology Services,
University of Wisconsin-River Falls
Case It! is a National Science Foundation-sponsored project to enhance case-based learning in high school and university biology courses worldwide through the use of molecular biology computer simulations and Internet conferencing. Students begin by playing the roles of laboratory technicians as they analyze DNA sequences associated with particular cases; then they play the roles of genetics counselors and family members as they discuss results of genetic testing, emphasizing ethical issues associated with the various cases.
As "lab technicians," students can choose cases from a variety of human genetic diseases including Alzheimer's disease, breast cancer, sickle-cell anemia, muscular dystrophy, cystic fibrosis, phenylketonuria, Huntington's chorea, and fragile-X syndrome. We originally obtained the appropriate DNA sequences for the various disease conditions from Genbank, a federal repository of genetic information, then modified the sequences to create multiple scenarios involving hypothetical "family members" being tested for the presence or absence of disease mutations. Although students use these pre-packaged cases for analysis, they have the option of creating their own cases. This is possible because the simulation we have developed is completely opened-ended and will work with any DNA sequence. Current capabilities of the simulation include DNA gel electrophoresis, Southern blotting, dot blotting, and PCR (polymerase chain reaction).Examples: Sickle-Cell Anemia and Huntington's Chorea
DNA analyses can either be run quickly or in a step-by-step fashion from the "lab bench." Figure 1 helps show how this is done, using a scenario from the sickle-cell anemia case as an example. Abnormally large fragments (the ones to the left) move more slowly than normal fragments (the ones to the right), and a "radioactive probe" is bound to the fragments of interest to make them visible on the Southern blot. In this example, the father and mother are both heterozygous for the sickle-cell mutation, since they carry both an abnormal and a normal gene. The daughter carries only the normal gene, but the unborn fetus carries only the sickle-cell gene.
|Fig. 1: Results of a Southern blot for one scenario of the sickle-cell anemia case, run from the "lab bench."|
As another example, the Southern blot for one scenario for the Huntington's chorea case is shown in Figure 2. In this scenario, the aunt, brother, and father are heterozygous for this condition, meaning that they have both a normal and an abnormal gene in each of their cells, and all will come down with disease symptoms since only one copy of this particular mutation is enough to cause the disease. Susan and the uncle have only normal genes and thus will not get Huntington's chorea.
|Fig. 2: Results of a Southern blot for one scenario of the Huntington's chorea case. Graphics such as this can be saved and then uploaded to a server at UW-River Falls via the Case It! web page editor.|
After using the Case It! computer simulation to examine DNA fragments for the presence or absence of mutations, students create "posters" for genetic counseling via a custom Web-page-building system that enables them to easily upload gel/blot images and text to a server located at the University of Wisconsin-River Falls. A tutorial for the web page editor can be viewed online. The poster and discussion forum associated with each team of students is accessible from the Case It! Launch Pad. Students play the role of genetics counselors when responding to questions sent to their forums and play the role of family members when sending messages to other forums.
A host of issues can be discussed at these "counseling sessions," including questions regarding the molecular biology of the disease, symptoms, treatment, and ethical ramifications. For example, if Susan talks her brother John into being tested for Huntington's disease, and if Susan tests negative but John tests positive, how would the genetics counselors deal with the hard feelings that might result? If a fetus tests positive for sickle-cell anemia and the family member asks about the possibility of an abortion, how should the genetics counselor respond?Class-testing
Class-testing currently includes students from three high schools (two in Wisconsin and one in Australia) and three universities (Campbell University, the University of Wisconsin-River Falls, and the University of London). At UW-RF, Case It! is used in three classes of Biology 100: Introductory Biology. Results of class-testing last year can be accessed from the Case It! Home Page; note that last year we used WebCT as the conferencing system, whereas this year we are using a new, custom conferencing system integrated into the Case It! Launch Pad.
We wish to expand this project to include additional high schools and universities in the U.S. and abroad. Educators wishing to participate in the project should contact Mark Bergland via e-mail at firstname.lastname@example.org. There is no cost to participate, as the project is supported by the Course and Curriculum Development program of the National Science Foundation (DUE Grants 9752268 and 9455425).
Note: Opinions expressed in this article are those of the authors and not necessarily those of the National Science Foundation.