NAME:______________________PERIOD:____DATE:________
Flow of Energy Through an Ecosystem
Directions: For each statement write true or false in the blank.
______1. An organism’s niche includes its habitat.
______2. Trophic levels describe the differences in size of the organisms in a
habitat.
______3. Carnivores obtain nutrients by eating other consumers.
______4. Organisms that feed on dead organisms are called scavengers.
______5. Humans are classified as carnivores.
______6. All of the energy available to organisms at each level of the food
chain stored.
______7. A food chain is the specific sequence in which organisms obtain
energy in an ecosystem.
______8. In an ecosystem, stored energy is generally transferred from one
trophic level to the trophic level directly below it.
______9. Food chains usually consist of eight or nine levels.
Directions: Choose that one best response. Write the letter of that choice in the
space provided.
______10. A food chain generally begins with:
A. autotroph
B. omnivore
C. decomposer D. heterotroph
______11. Interrelated food chains are called a:
A. food niche
B. food web
C. habitat
D. food chain
______12. Which group of organisms is responsible for releasing nutrients back
into the ecosystem so that the nutrients may be recycled by
producers?
A. insects
B. bacteria
C. mammals
D. phytoplankton
______13. The greatest amount of energy in an ecosystem is available to:
A. producers
B. primary consumers
C. secondary consumers
D. decomposers
______14. Energy that is lost at each trophic level of an ecosystem is
replenished by
A. heat
B. nutrients
C. sunlight
D. organisms
______15. Besides energy, what moves through the organisms at each trophic
level of an ecosystem?
A. organisms
B. nutrients
C. sunlight
D. cycles
______16. Autotrophs and heterotrophs use carbon molecules for energy and
A. photosynthesis
B. growth
C. decomposition
D. A and B
______17. What do plants use in photosynthesis to make carbon molecules?
A. carbon dioxide
B. carbohydrates
C. fertilizer
D. oxygen
______18. Heterotrophs get carbon molecules by
A. growing
B. feeding on other organisms
C. decaying
D. making the molecules themselves
Directions: Read each question or statement and answer it in the space
provided.
19. Explain why decomposers are necessary in an ecosystem?
20. Why are primary producers an essential component of an ecosystem?
21. In general, how does energy flow through an ecosystem? How does energy flow
relate to an organism’s trophic level?
22. Why do organisms at higher trophic levels generally consume more food than those
at lower levels?
23. Explain how a food chain differs from a food web.