Energy Pyramid Simulation

ENERGY PYRAMID SIMULATION

By Ida Swenson

 INTRODUCTION:

  One of the most difficult concepts for students to grasp is the energy pyramid.  Why is a triangle used?  Where does the energy go?  This simulation will help them understand what is happening and gets them out of their seats and involved in their learning.  It assists the learning of tactile/kinesthetic and spatial-visual learners.  If you add some sort of rhythmic music in the background as students are coming forward to take out the ‘energies’, it will help your musical learners.

PROCEDURE FOR OVER TEN STUDENTS:

MATERIALS NEEDED: large writing surface (blackboard) and chalk, corn starch packing peanuts, two gallon clear Ziploc bag, dishpan filled with water

 3x5 cards with ONE EACH of  the following: (Color coding can be useful.)

Sun, grasshopper, grass, frog, snake, hawk

Grass uses 2 ‘energies’ for metabolism

Grass uses 2 ‘energies’ for growth

Grass uses 3 ‘energies’ for reproduction

Grass uses 1 ‘energy’ for moving materials within itself

Grasshopper uses 3 ‘energies’ for metabolism

Grasshopper uses 3 energies for reproduction

Grasshopper uses 3 energies for growth

Grasshopper uses 5 energies to move around and get food

            Frog uses 4 ‘energies’ for metabolism

            Frog uses 5 ‘energies’ for reproduction

            Frog uses 4 ‘energies’ for growth

            Frog uses 11 ‘energies’ to move around and get food

            Snake uses 5 energies for metabolism

            Snake uses 6 ‘energies’ for reproduction

            Snake uses 4 ‘energies’ for growth

            Snake uses 6 ‘energies’ for moving around

            Snake uses 2 energies to molt

            Hawk uses 10 energies for metabolism    Why?

            Hawk uses 6 energies for growth

Hawk uses 20 energies for reproduction: making a nest, hatching the eggs, finding food for young

            Hawk uses 10 ‘energies’ for movement and getting food

            WHAT TO DO:  Fill Ziploc bag with peanuts.  Draw the energy pyramid on the blackboard and make the grass à grasshopper à frog à snake à hawk food chain.  Show where it fits in the pyramid.  Why is it a pyramid?  Hand out the cards, giving more than one card to some students so all are participating.  (Be sure your more distractible students get a hawk card to help them stay on task.   If you have a small class or a very short time, you may want to eliminate the snake from the food chain.)   What is the source of all the energy?  Call the sun to the front of the room.  Which organism can change the sun’s energy into food energy?  Call the grass up.  Will the grass get all the sun’s energy? (No, some goes to outer space, some is reflected, some warms us up and gives light.)  Ask for the each of the grass cards to come forward and take out their ‘energies’ and put them into the dishpan of water (representing heat in the atmosphere).  After each food chain member has used up their ‘energies’ for growth, metabolism, reproduction, and movement show how the level of energies has diminished by holding the bag up by one corner to give the triangular effect. 

 

PROCEDURE FOR TEN OR FEWER STUDENTS:

MATERIALS NEEDED: large writing surface (blackboard) and chalk, corn starch packing peanuts, two gallon clear Ziploc bag, dishpan filled with water, masking tape/labels/or over-the-head placards saying: sun, grass, grasshopper, frog, snake, metabolism, reproduction, circulation and movement.

WHAT TO DO:  Follow the procedure for the large group of students, except instead of handing out the cards, have each student take a label (Sun can have two since ‘his’ part is small.)  The bag of ‘energies’ will be passed from one member of the food chain to another, and the ‘metabolism’, ‘reproduction’, ‘movement and circulation’, and ‘growth’ people will come up and take their energies from each member of the food chain. 

 

CONCLUSIONS FOR ALL STUDENTS:

   After all of the cards (or food chain members) have been used up, discuss with the students the reason why a pyramid shape is most appropriate.  Should it be a narrow, tall triangle, or a long, flat triangle to be most accurate?  Give the ‘rule of thumb’ that it takes ten times as many organisms at each level to support the level above.  (Actually it takes many more.)   Where did the energy go?  Has it been lost? (A good chance to remind them of the law of conservation of energy.)   Show them the dishpan.  Where did the energy go?  Are the packing peanuts still there?  They have just changed form, just as the food energy used by the organism has been changed into kinetic energy and then to heat.

 

ELABORATIONS:  This is a good way to talk about many things, for example the high metabolism energy needs of warm-blooded animals.  It is also a good way to reinforce the importance of food in maintaining metabolism and circulation even in organisms which stay in one place.  The higher energy needs involved in caring for young is very evident.  If you have stickers you can use for each animal in the food chain, modify the activity to make it appropriate for the stickers.