Biology
Mini lab. Energy Transfer up the Food Chain:
A demonstrative activity
Materials Needed:
1000 mL Beakers (1 per lab station)
100 mL graduated cylinders (1 per station)
10 mL graduated cylinders (2 per station)
Water
Procedure:
1. Have students get into groups of 4. If there is an odd number of groups, then it is
okay to have a group of 3 or a group of 5 (this will be good for discussion).
2. Each group will consist of:
a.
b.
c.
d.
1 person representing algae; 1000mL cylinder
1 person representing mosquito larvae; 100mL cylinder
1 person representing walleyes (a type of fish); 10mL cylinder
1 person representing muskies (a type of bigger fish); 10mL cylinder
Note: if there is a group of 3, skip the muskies. If there is a group of 5, add in a person
representing “fishermen”.
3. The teacher represents the sun. He/she will go around the room and provide each
population of algae (designated students in each group) “energy”, represented by
1000 mL of water.
4. The student (algae) must then pour 90% of their water down the drain. This
represents losing energy due to heat/use. For instance: the “algae” would dump
out 900 mL.
5. The remaining 10% of water represents the usable energy that will get passed
onto the next trophic level when it is consumed by an organism in the next
tier/level. In the case of the first round, 100 mL gets passed onto the mosquito
larvae from the algae.
6. The mosquito larvae (100mL cylinder) should then pass on 10% of its energy to
the next organism and lose the remaining 90% of energy (water).
7. Continue until the last organism gets its “energy” from the food, following the
same concepts as with the others. Remember, each time the amount of energy
(water) should decrease by 90%.
8. This activity should be followed by a group discussion based on the following
questions.
**A fisherman should get .1mL (or 100uL); impossible without a pipet.
1
modified 2/16/2016
Biology
Discussion questions. To be answered IQIA in notebook.
1. Make a diagram. Use graduated cylinders and arrows to represent the steps of the
activity you just completed. Does this represent a food chain or food web? Explain.
2. How many trophic levels were in your group?
3. Which organism(s) represented the autotrophs? Heterotrophs?
4. Which organism(s) represented the consumers? Which were herbivores?
Carnivores?
5. Below your diagram you made in #1 write the names of the organisms which
represented each graduated cylinder.
6. If the algae had a 1000mL of water to start, how much water did each organism end
up with?
7. What percentage of the water in each cylinder actually got passed on to the next
organism?
8. What percentage of the water was lost at each level of the activity?
9. Explain why you think that not all the energy got passed on to the next organism. In
other words, what happens to the rest of the energy in what is eaten?
10. Summarize everything. On this planet, what is all life based on? Why? Why are
producers needed?
Discussion questions. To be answered IQIA in notebook.
1. Make a diagram. Use graduated cylinders and arrows to represent the steps of the
activity you just completed. Does this represent a food chain or food web? Explain.
2. How many trophic levels were in your group?
3. Which organism(s) represented the autotrophs? Heterotrophs?
4. Which organism(s) represented the consumers? Which were herbivores?
Carnivores?
5. Below your diagram you made in #1 write the names of the organisms which
represented each graduated cylinder.
6. If the algae had a 1000mL of water to start, how much water did each organism end
up with?
7. What percentage of the water in each cylinder actually got passed on to the next
organism?
8. What percentage of the water was lost at each level of the activity?
9. Explain why you think that not all the energy got passed on to the next organism. In
other words, what happens to the rest of the energy in what is eaten?
10. Summarize everything. On this planet, what is all life based on? Why? Why are
producers needed?
2
modified 2/16/2016