APES Food Web Computer lab Assignment
Name __________________________________
Relationships are all about Energy!
Read and review the information on the site below regarding food chains and energy flow.
http://users.rcn.com/jkimball.ma.ultranet/BiologyPages/F/FoodChains.html
1. Define Autotroph and provide a synonym ____________________________________________________
__________________________________________________________________________________________
2. Herbivores are also called ________________________________.
3. Carnivores are also called ________________________________.
4. Omnivores can be either ______________________ or _________________________.
5. Differentiate between Gross Primary Productivity and Net Primary Productivity. Explain why NPP is so much
less than GPP. You may need to look up other sites or in ppt. to gain a clearer understanding.
6. Calculate the Conversion Efficiencies for the following tropic level transfers of energy in a given food chain.
(something eating something else).
Energy Transfer Between Tropic Levels
Net Productivity at different tropic levels
Conversion
Efficiency
Lower tropic level
Higher tropic level

Organism A
2187cal
Organism B
25 cal

Organism K
11000cal
Organism L
3200 cal
7. One of the above pairings represents a Producer Primary consumer energy transfer. The other represents
primary consumer  secondary consumer energy transfer. Which is which? Defend your selection.
8. Energy lost at each link of the food chain is ultimately lost as ______________.
9. Summarize and diagram the 3 different food web pyramids in the space below. (Energy, Biomass, Numbers)
APES Food Web Computer lab Assignment
Name __________________________________
10. We have focused on the energy pyramid. Provide an application/argument for using the biomass and numbers
pyramids.
11. Scroll back up to the energy pyramid. Follow the Link to an example. To learn about bioaccumulation. In your
own words, explain why a bird at the top of the food web can have a higher concentration of DDT in it’s tissues
than organisms at lower tropic levels.
Access the site listed below.
http://www.oceanlink.info/biodiversity/foodweb/foodweb.html
12. Read the introduction and then try your hand at creating a food web with the information provided. Write each of
the organism’s name and circle it, then connect the arrows.
** Arrows mean “eaten by” and therefore, generally, point toward the top of the food web. NOTE: Leave out
the scavengers and decomposers for simplicity’s purpose – only include the other 8 organisms!
13. Now eliminate one or more organisms and see how the food web might change. Identify the organism you
eliminated and indicate the result.