Energy and Ecosystems Complete Notes

  • Created by: Megan
  • Created on: 05-06-15 16:44

Food Chains

  • Producers - photosynthetic organisms that manufacture oganic substances
  • Consumers - obtain energy by feeding on other organisms. Primary consumers directly eat producers. Secondary consumers eat primary consumers. Tertiary consumers eat scondary consumers. Secondary and Tertiary consumers are usually predators but can also be scavengers or parasites
  • Decomposers - break down complex materials into single components
  • Food chain = feeding relationship between producers and consumers
  • Trophic level = each stage of food chain

Energy losses in food chains

  • Suns energy reflected back into space, not all wavelengths of light can be absorbed by chlorophyll, light may not fall on a chlorophyll molecule.
  • Photosynthesis is not very efficient
  • Some of the organism is not eaten
  • Some parts are indigestable so lost as faeces
  • Some energy losses as heat from respiration - maintaining body temperature, movement etc

Net Production = Gross Production - Respiratory Losses

Energy Transfer = energy available after the


No comments have yet been made