Trophic levels

• What are trophic levels?

  Different levels within a food chain
• What type of organisms are always 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 organisms in the third trophic level called?

  Secondary consumers
• What do secondary consumers primarily eat?

  Other animals
• What are organisms in the fourth trophic level called?

  Tertiary consumers
• What does the term "tertiary" refer to in trophic levels?

  It means third level of consumers
• Why are there usually no more than 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 1 has 1,000 joules?

  10 joules
• What is the energy in trophic level 4 if level 1 has 1,000 joules?

  1 joule
• What are apex predators?

  Carnivores with no natural predators
• Where do omnivores fit in the trophic levels?

  Generally in trophic level 3
• What do decomposers do?

  Help decompose dead matter
• What is the role of decomposers in the ecosystem?

  Recycle nutrients back into the ground
• What are the different trophic levels in a food chain?

  1. Trophic Level 1: Producers (plants, algae)
  2. Trophic Level 2: Primary Consumers (herbivores)
  3. Trophic Level 3: Secondary Consumers (carnivores)
  4. Trophic Level 4: Tertiary Consumers (carnivores)
  5. Apex Predators: Top carnivores with no predators
• What is the energy transfer efficiency between trophic levels?

  • Only about 10% of energy is transferred
  • Energy decreases significantly at each level
  • Example: 1,000 joules → 100 joules → 10 joules → 1 joule
• What distinguishes omnivores from other consumers?

  • Eat both producers and other animals
  • Generally placed in trophic level 3
  • Not a perfect fit due to varied diet
• What is the function of decomposers in an ecosystem?

  • Decompose dead plant and animal matter
  • Recycle nutrients back into the soil
  • Support producers by enriching the ground