4.6 - Trophic Levels

• What are trophic levels?

  Different levels within a food chain
• What type of organisms are found at the first trophic level?

  Producers like plants or algae
• Why are producers called producers?

  They use photosynthesis to produce food
• What do primary consumers eat?

  Plants and algae
• What are primary consumers also known as?

  Herbivores
• What are secondary consumers known as?

  Carnivores
• What does the term "tertiary consumers" refer to?

  Third level of consumers in the chain
• Why do food chains usually have only four or five trophic levels?

  Energy gets lost at each level
• What percentage of energy is passed to the next trophic level?

  About 10 percent
• If trophic level 1 has 1,000 joules, how much energy is in trophic level 2?

  100 joules
• How much energy is in trophic level 3 if level 2 has 100 joules?

  10 joules
• What is the energy in trophic level 4 if level 3 has 10 joules?

  1 joule
• What are apex predators?

  Carnivores with no natural predators
• Where are omnivores typically placed in trophic levels?

  In trophic level 3
• Why is the placement of omnivores not a perfect fit?

  They eat both producers and consumers
• What roles do decomposers and detritivores play in ecosystems?

  • Decompose dead plant and animal matter
  • Recycle nutrients back into the ground
  • Help producers use nutrients again
• What do detritivores consume?

  Dead organic matter
• How do decomposers benefit the environment?

  They recycle nutrients for producers