This investigative case module was prepared as part of a BioQUEST faculty development workshop entitled PRISM Workshop: Implementing Investigative Case-Based Learning at Center for Science Education in June 2003. The cases, resources, and implementation strategies were developed by participants for use with their own students. We invite you to adopt and adapt the following materials.

The BioQUEST Curriculum Consortium is committed to the reform of undergraduate biology instruction through an emphasis on engaging students in realistic scientific practices. This approach is sometimes characterized as an inquiry driven approach and is captured in BioQUEST's three P's (problem-posing, problem-solving, and peer-persuasion). As part of this workshop groups of faculty were encouraged to initiate innovative curricular projects. We are sharing these works in progress in the hope that they will stimulate further exploration, collaboration and development. Please see the following links for additional information:

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Investigative Cases
The Case: Water Works

Scene 1 (Thursday after school starts):

Shelby and her college roommate, Twanda, head to Target after lunch to purchase the last of the items they need to finish decorating their dormroom. While deciding on matching comforters for their bed, Shelby suddenly feels very dizzy and has painful abdominal cramping. She tells Twanda to pick out a comforter while she’s in the restroom. She gets sick in the bathroom with bad watery diarrhea. After washing her hands she heads back to the main section of the store and finds Twanda at the checkout.

“We gotta get home,” says Shelby. “I’m really sick. I think its something I ate at lunch.”

When she returns to her dorm room, she checks her phone messages. Carly, Her best friend from high school, who is attending Georgia Southern University, has left her a message.

“Hey Shelb, hope everything’s going well there and that you’ve got your dorm room decorated. I haven’t been able to decorate mine yet; I’ve been way to sick. Call me.”

Scene 2: Two days later

Shelby is still sick and at the urgings of her roommate, goes to the university health services center. She complains to the doctor that she is extremely fatigued and is having bad diarrhea. The doctor’s medical chart notes are given below:

Temperature: 98.5
Blood pressure: 120/80
Heart rate: 85 beats per minute
Skin: cool hands and feet, eyes appear slightly sunken, skin has reduced elasticity (Skin doesn’t bounce back quickly when lightly pinched and released), dry mouth
Age: 18
Sex: Female

Notes: Patient complains of dry mouth, fatigue, and watery diarrhea (more than 10 episodes a day). Patient says disease onset occurred 2 days ago after eating lunch in the university cafeteria. Patient has eaten all meals at the university cafeteria since arriving on campus on Monday for the start of the fall semester. On the day of disease onset, she had eggs and toast for breakfast with coffee and approximately 2 tablespoons of coffemate. For lunch she consumed tuna fish salad over lettuce, French fries with ketchup, a chocolate yogurt from the frozen yogurt machine, and a diet Sprite.

Scene 3:
Doctor’s notes continued:

Notes: To date, no other students at the university have presented with similar symptoms. Patient spent the week before school started, hiking the Appalachian trail between Amicalola Falls and Blood Mountain with a high school environmental science club. She remembers drinking unfiltered water from a spring while on the trip.

Stool sample, admittance to hospital for IV fluids and monitoring.

Scene 4:
You have been asked to assess the water from the spring where Shelby drank unfiltered water.

(Insert water lab) Students will analyze pond water for various aquatic organisms and identify and classify observed organisms. They will investigate as to whether the organisms in their sample can cause symptoms similar to Shelby's when ingested.

Scene 5: Shelby's conditioning is worsening and the doctor needs to know the pathogenic organism so he can prescribe the correct medication. A member of your group has isolated a suspicious organism and has prepared a photograph for you to use.

Identify the organism. Research the proper treatment and prevention of infection from such an organism.

Case Author:
Suzy Sumrall
Angela Wade
Janel Chatraw Emory University:Center for Science Education
Molly Embree
Amy Webb

Case Analysis

Learning Issues:
The digestive tract -- organs, functions, and disorders that can cause diarrhea
How diarrhea causes dehydration
Identify and classify aquatic organisms, specifically members of the plant, fungus, and protist kingdoms
Identify pathogenic members of the protist, fungus, and plant kingdom
Proper lab techniques for microscope and taxonomic key use.
Techniques or habits that can reduce risk of infection

Option: Include a know / need to know chart like the one below:

What do you know?
What do you need to know?

Learning Goals


Understanding how pathogens make you sick
Understanding actions that can be taken to reduce risk of getting pathogen.
Understanding properties of protists and how protists differ from members of other kingdoms
lab techniques for using a microscope and classifying aquatic organisms


1. Scientific Inquiry Skills: Uses process skills of observing, classifying, communicating, predicting, inferring, identifying variables. Also uses recording, analyzing,constructing hypothesis, and drawing conclusions
4. Reference Skills: Selects and uses multiple types of print and nonprint sources for inormation on science concepts
7. Human Body--Digestive System: Explains and describes the features, functions, and organs or the digestive system.
8. Human Body -- Immune Function: Describes body's line of defense against pathogens
13. Classification: Classification of living things by similarities in structure, behavior, food needs, chemical makeup into kingdoms, phyla, classes, orders, families, genera, and species
15. Monerans, Protists, Fungus: Classification of organisms by kingdom and identification of harmful and beneficial effects of organisms in these three kingdoms


Investigations and Activities

Aquatic Organisms Lab:

Students are given a sample of pond water.
They must prepare a wet mount slide and examine the sample under different magnifications using a light microscope.
They will classify the organisms observed according to kingdom and list the key characteristics of each representative kingdom.
They will use a taxonomic key to further identify organisms in their sample and will research three-five organisms in their sample for possible pathogenic potential.

Scanning Electron Micrograph: Students will use the EM picture of giardia and a taxonomic key to identify the organism.
They will then use internet searches to identify the treatment and prevention of infection by Giardia.



Students will usually obtain additional references or resources
to help answer or explore their questions.

Special Data Items

1. giardn3.gif


Student Products

Artifacts will tie in with student's Social Studies class.
Students will put together pamphlets that highlight water borne diseases and their causative pathogens in specific countries in Africa or Asia.
Students will choose a specific country and identify 3-5 waterborne diseases, their causative pathogen, risk factors for infection, prevelance, methods that can be used to prevent infection, and barriers to implementing those methods that face a specific country.

Assessment and Evaluation Plan



Course name:
Middle School Life Sciences
Likely sequence in syllabus:
During microorganisms unit, when teaching monerans, protists, and fungus
Time during term:
late fall
2 weeks
Students in course:
all levels
Collaborative elements:
lab work to identify aquatic organisms, identifying EM picture of giardia
Additional notes:



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