How materials are cycled

Cards (7)

  • describe how materials cycle through the living and non-living components of an ecosystem
    • organisms take in elements from their surroundings
    • elements converted to complex molecules which become biomass
    • elements transferred along food chains
    • elements returned to environment during excretion and decomposition of dead organisms
  • give 3 molecules which are cycled through ecosystems
    • oxygen
    • carbon dioxide
    • water
  • describe the carbon cycle
    • plants fix CO2 into organic molecules during photosynthesis
    • organic carbon-containing molecules are passed onto organisms that eat the plants
    • CO2 is released back into the atmosphere by respiration from animals and plants
    • burning fossil fuels also releases CO2
  • why is the carbon cycle important?
    carbon-containing molecules such as glucose are important for living organisms to grow and provide energy for vital functions within cells
  • describe the water cycle
    • water from lakes and oceans evaporates
    • evaporated water condenses into clouds and returns to earth as precipitation
    • water from precipitation is useful for life on land
    • water then returns to rivers and oceans through surface runoff
  • why is the water cycle important?
    living organisms require water and the water cycle provides organisms on land with a continuous supply of water
  • why are microorganisms important for the cycling of materials through an ecosystem?
    • return carbon to the environment by releasing CO2 through respiration while they decompose dead matter
    • decomposition of dead matter in soil returns mineral ions to the environment for other organisms to use