AP Biology / Unit 8: Ecology

8.2 Energy Flow Through Ecosystems

3 practice questions

Notes

Energy flows one way: sun → producers → consumers → decomposers.

  • About 10% of energy passes to the next trophic level; the rest is lost as heat.
  • Matter (carbon, nitrogen) cycles.
  • Endotherms use more energy to keep temperature than ectotherms.
Producers: 10,000 kcalPrimary consumers: 1,000 kcalSecondary consumers: 100 kcalTertiary consumers: 10 kcal
About 10% of energy moves up each level.

Practice

Producers have 10,000 kcal. About how much reaches secondary consumers?
Most energy at each level is lost as:
Decomposers are important because they:

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