ENERGY PYRAMID SIMULATION
By Ida Swenson
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.
