Energy Flow in Ecosystems
Explore the concepts of energy flow, food chains, food webs, and ecological pyramids in ecosystems.
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Energy Flow in Ecosystems
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Read each question carefully and answer to the best of your ability. Show all your work for calculations.
1. What is the primary source of energy for almost all ecosystems on Earth?
Geothermal energy
Chemical energy
Solar energy
Nuclear energy
2. Which trophic level contains organisms that produce their own food?
Primary consumers
Producers
Secondary consumers
Decomposers
3. The transfer of energy from one organism to another in an ecosystem is called a .
4. Organisms that feed on dead organic matter are known as .
5. Only about percent of energy is transferred from one trophic level to the next.
6. Observe the food web below. Identify one producer, one primary consumer, and one secondary consumer from the food web.

Producer:
Primary Consumer:
Secondary Consumer:
7. Decomposers are essential for recycling nutrients back into the ecosystem.
True
False
8. An ecological pyramid of biomass typically shows the greatest biomass at the top trophic level.
True
False
9. Explain the difference between a food chain and a food web. Why are food webs generally more stable than food chains?