Food Chains

• What can an ecosystem be divided into?

  Trophic levels
• What are the trophic levels in an ecosystem?

  1. Producer
  2. Primary consumer
  3. Secondary consumer
  4. Tertiary consumer
  5. Quaternary consumer
• What are producers in an ecosystem?

  Plants and algae that make their own food
• What are primary consumers?

  Animals that eat producers
• What type of animals are secondary consumers?

  Animals that eat herbivores
• What percentage of biomass is passed on to the next trophic level?

  10%
• How is biomass lost in an ecosystem?

  • In feces: not all ingested material is absorbed
  • Not all parts of an organism can be digested (e.g., bones, claws)
  • In urine: lost as waste (e.g., water and urea)
• What is the formula for percentage efficiency transfer?

  Percentage efficiency transfer = $\frac{\text{biomass in higher trophic level}}{\text{biomass in lower trophic level}} \times 100$
• If a lower trophic level has 1000 kg of biomass, how much is passed to the next level?

  100 kg