Grade: Senior
Subject: Science

#3354. A Tale of Two Reactors

Science, level: Senior
Posted Tue Feb 1 10:23:01 PST 2005 by Jenna Baker (
Liberty High School, Liberty, USA
Materials Required: 3 x 5 index cards, pens, sticky tabs
Activity Time: 30 minutes
Concepts Taught: Trophic Levels

Grade Level : 10th

Standards: SC Standards (II D 2 a, II E 4)

Objective : Students will be able to track the effects of pollution through an ecosystem by understanding the different trophic levels.

Background: The basis of this activity is understanding the food chai
n and how each organism is affected when something goes wrong with the environment. This activity will be role-play where the students become members of the food chain in a certain location. A polluting factor is introduced and the members of the different trophic levels will suffer varying degrees of damage due to that pollution. The beauty of the activity is that you can tailor it to fit your area, region, or specific types of pollution that may be more common in your part of the world. The teacher may want to make up their own scenario using the basic components included in the activity.

The story: The scenario you present to your class must have the following components: at least two towns, a river, an industrial plant that may pollute the environment, and various organisms in a variety of trophic levels. These may include several types of vegetation, some water organisms such as algae and fish. You also will need herbivores, omnivores, carnivores, and especially a top carnivore such as a bird of prey or a big cat. Humans must also be included in the activity. The number of humans you use may be based on the number of students in your class. It is definitely recommended that you develop your own story including towns that are actually in your area and organisms that are native to your part of the world. You must also designate at the beginning, which organisms eat what so there is no confusion.

1. Designate areas of your classroom as the stream or river, the town and the industrial plant. I use computers to represent my towns, the overhead as my industry and arrange the desks in a way to mimic a river.
2. You will then assign the students in the class to an organism. Place the student according to your scenario. Each student is given an index card that has their organism's name on it.
3. You then read the scenario to that the class and tell them that the industry has polluted the river, you must go around to all the of the organism in the river and attached the sticky tabs (they represent pollution) to those index cards. You also attach a few of the sticky tabs on the vegetation on the banks of the river.
4. You then allow the food chain to progress as it would during the course of nature. The students will role play their organism until they are eaten.
5. If all works as it should, the top carnivore should have all if not most of the sticky tabs, while the humans have some of them.
6. You may want to repeat this run through a couple of times to make sure the students understand what is happening.
7. After the role playing is complete, review with the class what has happened. Ask them which member of the food chain should have the most pollution tags and why. This is a question they should be able to answer after the activity. Also, have the students classify each organism into their proper level or type of organism.