The Carbon Cycle

• What is the starting point of the carbon cycle?

  Carbon dioxide in the atmosphere
• How does carbon enter the carbon cycle?

  Through photosynthesis
• What do plants combine with carbon dioxide during photosynthesis?

  Water
• What is produced during photosynthesis?

  Sugar glucose
• What type of energy is used in photosynthesis?

  Light energy
• Who carries out photosynthesis?

  Plants and algae
• What process returns carbon dioxide to the atmosphere?

  Aerobic respiration
• What are the two key processes in the carbon cycle?

  Photosynthesis and respiration
• What happens to carbon in plants and algae after photosynthesis?

  It is used to make carbohydrates, fats, and proteins
• What do plants and algae do with some of the carbon they take in?

  They respire
• What happens to carbon when animals eat plants?

  It becomes part of their cells
• What do animals release back to the atmosphere?

  Carbon dioxide
• What happens to animals and plants after they die?

  They are broken down by decomposers
• Who breaks down dead remains and waste products?

  Decomposing microorganisms
• What do decomposers release back to the atmosphere?

  Carbon dioxide
• What do decomposers release to the soil?

  Mineral ions
• What can happen to carbon in dead remains under certain conditions?

  It can be converted to fossil fuels
• How long does it take for carbon to be trapped as fossil fuels?

  Millions of years
• What has been happening to fossil fuels over the last 200 years?

  Humans have been burning them
• What is released back to the atmosphere when fossil fuels are burned?

  Carbon dioxide
• What is the role of decomposers in the ecosystem?

  They cycle materials and return carbon
• During the formation of fossil fuels what do they take in?

  $CO_2$
• How does $CO_2$ enter the ecosystem?


  through photosynthesis
• The Carbon Cycle 


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• What are the main processes in the carbon cycle?

  • Photosynthesis: Carbon dioxide is converted to glucose.
  • Respiration: Carbon dioxide is released back into the atmosphere.
  • Decomposition: Dead remains are broken down, returning carbon to the atmosphere.
• What roles do decomposers play in the ecosystem?

  • Break down dead remains and waste products
  • Return carbon to the atmosphere as carbon dioxide
  • Release mineral ions to the soil
• What are the consequences of a lack of oxygen for decomposers?

  • Decomposers cannot function effectively
  • Carbon in dead remains may convert to fossil fuels