The Great Waste Debate  




Core Goals | Overview | Teacher Directions | Materials/Time Required

Subject: Biology

Maryland Science Core Expectation (Concepts of Biology): The student will investigate the interdependence of diverse living organisms and their interactions with the components of the biosphere.

Maryland Science Core Expectation (Skills and Processes): The student will pose scientific questions and suggest experimental (computational) approaches to provide answers to questions.

Maryland Mathematics Core Expectation (Functions and Algebra): The student will model and interpret real-world situations, using the language of mathematics and appropriate technology.

Potential Cross-Curricular Connections: Environmental Science

Activity/Learning Indicator Match

Activities Learning Indicators

Activity 1 The student will investigate how natural and man-made changes in environmental conditions will affect pollution. The student will represent patterns and functional relationships in a table, as a graph, and/or by mathematical expression.

Activity 2 The student will describe how the graphical model of a non-linear function represents a given problem and will estimate the solution.

Activity 3 The student will formulate and test a working hypothesis.

Activity 4 The student will formulate and test a working hypothesis.


This task enables the students to use a computer model to test whether cow waste or commercial fertilizer introduces more phosphates and nitrogen into the Chesapeake Bay. The model is set up to analyze the same 100 acres used in two different ways: for housing or for a dairy farm. For the sake of simplicity, the dissipation of the phosphates and nitrogen is not shown. An advanced class would want to investigate that aspect of the model to make it more realistic.

Teacher Directions

After discussing the impact of phosphates and nitrogen on the health of the Chesapeake Bay, introduce the students to STELLATM by demonstrating the appropriate use of the software with a simple model. The students may work alone or in pairs, depending on computer availability.

Materials Required:     The Great Waste Debate Model and STELLATM, a system dynamics programming language.

Estimated Time:     4 class periods (of 45 minutes each)

Student Activities:     Activity 1 | Activity 2 | Activity 3 | Activity 4

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