Biogeochemical Cycles

Using fewer fossil fuels could help restore equilibrium to the carbon cycle. What does "equilibrium" mean?

• Oxygen
• Balance
• Resources
• Sinks

How does an increase in carbon dioxide lead to global warming?

• by trapping the Sun's heat in the atmosphere
• by causing very hot volcanic eruptions
• by catching fire within the atmosphere
• by increasing the amount of carbon in Earth's crust

What effect does the Sun have on surface water?

• it causes it to freeze
• it causes it to rain
• it causes it to sink
• it causes it to evaporate

Which of the following processes does not produce carbon dioxide?

• Photosynthesis
• Animal Respiration
• Burning Fossil Fuels

How do living organisms return carbon to the atmosphere in the carbon cycle?

• nitrogen fixation
• respiration
• denitrification
• photosynthesis

Identify the cycle pictured

• Water cycle
• Carbon cycle
• Nitrogen cycle
• Phosphorus cycle

In the carbon cycle, what do plants and other producers take in when they carry out photosynthesis?

• carbon dioxide
• phosphorus
• oxygen
• nitrogen

True or False: Nitrogen gas in the atmosphere is useable by plants and animals.

• True
• False

What cycle is demonstrated in this diagram?

• Carbon cycle
• Nitrogen cycle
• Water cycle
• Phosphorous cycle

Identify the cycle pictured

• Carbon cycle
• Nitrogen cycle
• Water cycle
• Phosphorus cycle