Stimulating Understanding of Computational science through Collaboration, Exploration, Experiment, and Discovery for students with Hearing Impairments
Project Proposal
For Students!
For Teachers!
For Interpreters!
What's New?
overview Objectives Prerequisites activities/materials Notes  Extension Resources

For Teachers!

Daphnia and Algae: a Study of Pond Dynamics


Daphnia and algae are small freshwater organisms. They can be raised in the classroom. They also play an important role in ponds and streams. This lesson uses a STELLA model to explore how they interact with each other and their environment. The lesson demonstrates a classic predator-prey relationship. 

Goals and objectives: 

This lesson addresses these National Science Education Standards:

Organisms both cooperate and compete in ecosystems. The interrelationships and interdependencies of these organisms may generate ecosystems that
are stable for hundreds or thousands of years. 

Living organisms have the capacity to produce populations of infinite size, but environments and resources are finite. This fundamental tension has
profound effects on the interactions between organisms. 

The distribution and abundance of organisms and populations in ecosystems are limited by the availability of matter and energy and the ability of the
ecosystem to recycle materials. 


Student Prerequisites: 

Students need to be familiar with the use of a computer mouse  

Materials Needed: 

Computers with STELLA  and Internet access or CD with this lesson.

If you use PCs you can down load a free zipped version of the model used in this lesson.

You will need to unzip the model. A free evaluation version of WinZip is available at

If you use Macs you can down load a free compressed version of the model used in this lesson.

You will need to decompress the model. A free StuffIt Expander is available at

You will need STELLA to use the lesson. If your class doesn't have a copy of STELLA you can down load a free save disabled version.  


Developed by
The Shodor Education Foundation, Inc.

Copyright © 1999-2001 by The Shodor Education Foundation, Inc.

This project is supported, in part,
by the

National Science Foundation

Opinions expressed are those of the authors
and not necessarily those of the National Science Foundation.

Last Update: Saturday, 16-Feb-2002 13:29:11 EST
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