material cycles

• the carbon cycle

  1. carbon dioxide is removed formt he atmosphere via photosynthesis of plants - used to make glucose
  2. plants respire returning Co2
  3. when plants are eaten by animals carbon becomes part of the food chain
  4. when the plant or animal dies detritus feeders feed on the remains and respire
  5. waste produced by animals is also broken down
  6. combustion of wood and fossil fuels also release CO2 back into the air
• the water cycle

  1. energy from the sun makes water evaporate turning it into water vapour. water vapour also transpires from plants
  2. the warm vapour rises cools and condenses to form clouds
  3. water falls from the clouds as precipitation where it provides freshwater for plants and animals
  4. it then drains to the sea and the cycles starts over
• environmental changes that affect the distribution of organisms?

  • temperature = distribution of bird species changes due to temperature rises
  • availability of water = distribution of animals in the tropics changes depending on the wet and dry seasons
  • composition of atmospheric gases = distribution changes due to air pollution levels
• how do microorganisms help to cycle materials?

  • they return carbon to the atmosphere as carbon dioxide and mineral ions to the soil
• what is the importance of the water cycle?

  • provides fresh water for plants and animals on land before draining to the sea, it is continuously evaporated and precipitated
• what is the importance of the carbon cycle?

  • returns carbon from organisms to the atmosphere as carbon dioxide to be used by plants in photosynthesis