Understanding the Carbon Cycle

What is the carbon cycle?

• The movement of oxygen through the environment

• The flow of carbon atoms between living organisms, the atmosphere, oceans, and the earth

• The process of burning fossil fuels

• The circulation of nitrogen in the atmosphere

What is the main form of carbon found in the atmosphere?

• Carbon dioxide

• Carbon monoxide

• Methane

• Ozone

What role do plants play in the carbon cycle?

• They release carbon dioxide into the atmosphere during photosynthesis

• They absorb carbon dioxide during photosynthesis

• They convert methane into oxygen

• They store carbon dioxide in their roots

What process do plants use to absorb carbon dioxide from the atmosphere?

• Respiration

• Photosynthesis

• Combustion

• Decomposition

Which process releases carbon back into the atmosphere?

• Respiration

• Photosynthesis

• Carbon fixation

• Nitrogen fixation

How do animals contribute to the carbon cycle?

• They absorb carbon dioxide from the atmosphere

• They produce carbon dioxide during respiration

• They produce oxygen during respiration

• They store carbon in their muscles

What is a major carbon reservoir that stores carbon for long periods of time?

• Forests

• Oceans

• The atmosphere

• Volcanoes

Which of the following is a carbon sink?

• Deforested land

• Cement factories

• The ocean

• Burning fossil fuels

What happens to carbon when animals or plants die?

• It stays locked in the body permanently

• It is released immediately into the atmosphere

• It becomes part of the soil and may be released through decomposition

• It is destroyed completely

What is the process by which decomposers break down dead material, releasing carbon dioxide?

• Combustion

• Photosynthesis

• Respiration

• Decomposition