Modeling Energy in Ecosystems
Virtual Lab
Record evidence you completed each task in your lab book. Be sure
to have titles and headings so the information will make sense later
when you read it.
Go to the site:
http://www.mhhe.com/biosci/genbio/virtual_labs/BL_02/BL_02.html
1. Explore the simulation and read the writing on the left about
energy flow through an ecosystem. (collect evidence you did
this)
2. There are five types of ecosystems modeled, try to place the
organisms into the correct “trophic level” on each model.
Example: drag all the producers (plants) to the part on the
pyramid which reads producers, If you’re not sure which
organisms are herbivores, you can look them up on the
computer or use the “check” feature. (collect evidence you did
this for all five ecosystems)
3. Pick a favored ecosystem, just one. Complete the placement
of al the organisms.
a. Sketch the simulation once it’s complete.
b. Record the data for “Pyramid of Numbers” and “Pyramid
of Energy.”
c. Explain what you understand these numbers to mean.
4. Explain the following terms in your lab book and give many
examples. Producers, First Order Heterotroph, Second Order
Heterotroph, Third Order Heterotrophs, Decomposers.
5. Answer the following questions in your lab book. Write with
complete ideas. Sketch drawings and show math calculations
as needed.
a. Suggest reasons why the information represented in the
pyramid of numbers of animals of one of the ecosystems
you studied may not truly represent that ecosystem.
b. According to your data, what is the ratio of third-order
consumers to producers? Explain your answer.
c. Compare and contrast two of the ecosystems you
studied. How is the energy conversion efficiency similar or
different?
d. Does the population size increase or decrease at higher
trophic levels in the pyramid of numbers of an ecosystem
consisting of a tree, insects (that are herbivores) and
birds feeding on the insects? Explain your answer.
e. What might happen to an ecological pyramid of numbers
in a forest ecosystem if most of the deer were killed due
to hunting by people and disease?
f. What would happen to an ecosystem if the decomposers
disappeared?
g. Could there be a food chain without herbivores and
carnivores?