Name __________________________________________ Date _______________ Period __________
Unit 1 Lab: Energy and Pyramids Using Water
Background: At this point, we have explored the transfer of energy between trophic levels… and realized
that the energy transfer is not exactly the most efficient process. Now it is time to see this energy transfer
happen in real life!
Procedure: You will start out with 4 buckets filled with water to represent the Sun, Producers, Primary
Consumers, and Secondary Consumers, see below.
Sun
Producers
Primary Consumers
Secondary Consumers
The large bucket will represent the Sun and the three smaller buckets will represent the trophic levels.
After you perform the experiment as it is explained below, you must fill out the Part 1 data table and
answer the Analysis Questions. Then we can continue to Part 2, where you must fill out the Part 2 data
table and answer the Analysis Questions.
PART 1
Representing the Trophic Levels:
 Three volunteers will represent the Producers. They will run with cups of water from the Sun to
the Producer bucket.
 Two volunteers will represent the Primary Consumers. They will run with cups full of water from
the Producer bucket to the Primary Consumer bucket (but, these cups will have a small hole in the
bottom)
 Finally, one volunteer will represent the Secondary Consumer. He or she will run with cups full
of water from the Primary Consumer bucket to the Secondary Consumer bucket (but, these cups
will have two small holes in the bottom)
Data Table
Sun
Producers
Primary
Consumers
Secondary
Consumers
Amount of water
present (Liters)
Analysis Questions
1. What does the water represent? ________________________________________________________
2. What is the ultimate source of energy to the Earth? Is it unlimited? ___________________________
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3. What types of organisms convert the Sun’s energy into organic matter for themselves and other
organisms? ________________________________________________________________________
4. What is the process mentioned in Question 3 referred to as? _________________________________
5. Why do you think there were less amount of secondary consumers than primary consumers and less
primary consumers than producers? ________________________________________________________
_____________________________________________________________________________________
_____________________________________________________________________________________
6. Did all water from one level pass on to the next level? ______________________________________
7. What does the spillage of water represent? _______________________________________________
_____________________________________________________________________________________
8. How does this represent the transfer of energy between trophic levels? _________________________
_____________________________________________________________________________________
9. As energy transfers between levels, only 10% is passed on to the next level. Write two examples of
how energy may be lost between trophic levels.
1)
2)
PART 2
Now you will repeat this same activity, but with a little twist. There will still be 4 buckets (Sun,
Producers, Primary Consumers, and Secondary Consumers), but the water will now represent BIOMASS.
We will also add Styrofoam peanuts to the buckets.
Data Table
Biomass (Liters of
Water)
Amount of Styrofoam
Peanuts (#)
Producers
Primary Consumers
Secondary Consumers
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Concentration of
Styrofoam Peanuts
(# of peanuts/biomass)
10. What do you know about the base of the biomass pyramid? Is it the largest or smallest?
_____________________________________________________________________________________
_____________________________________________________________________________________
11. Based on your answer from Question 10, why do you think the base of the pyramid is either the
largest or smallest? _____________________________________________________________________
_____________________________________________________________________________________
12. What do you think the Styrofoam Peanuts represent? ______________________________________
____________________________________________________________________________________
13. Which trophic level has the highest concentration of Styrofoam peanuts? ______________________
14. Which trophic level has the lowest concentration of Styrofoam peanuts? ______________________
Extensions:
15. Let’s say the Styrofoam peanuts represent a pollutant like pesticides. What conclusions can you
make about the concentrations of pollutants as you move up in trophic levels and up the food chain.
___________________________________________________________________________________
___________________________________________________________________________________
___________________________________________________________________________________
16. Pregnant women are warned by the government not to eat too much swordfish or shark, which are
very high in the food chain. Mercury in marine and aquatic fish provides a health hazard to humans.
Why do you think pregnant women are warned against swordfish and shark, but not necessarily against
seafood like shrimp?
___________________________________________________________________________________
___________________________________________________________________________________
___________________________________________________________________________________
___________________________________________________________________________________
___________________________________________________________________________________
Graphing:
Make a graph to display the data: energy, biomass, OR concentration of pollutant. You can choose which
data to graph (you must only prepare one graph). Remember that a graph must include a TITLE, LABEL
X and Y AXIS, and a KEY. Also think about which type of graph would be most appropriate to display
this type of data. (please make your graph on the back of this page)
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