Cycles Carbon Nitrogen Phosphorus

When humans burn fossil fuels, most of the carbon quickly enters the                       as carbon dioxide.

• Water
• Atmosphere
• Sun
• Air

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

• respiration and photosynthesis
•  decomposition and respiration

In the carbon cycle, producers take in the gas __

• carbon dioxide
• oxygen
• nitrogen
• carbon monoxide

In what process is Carbon transformed into chemical energy?

• Photosynthesis
• Respiration
• Primary Production
• Secondary Production

What is happening at 1?

• respiration: releasing CO2
• decomposing CO2 in the soil
• photosynthesis: absorbing CO2
• turning CO2 from the atmosphere into organic molecules

What is the role of decomposers in an Ecosystem? 

• They recycle matter and nutrients to form fossil fuels
• They are burn and release as carbon dioxide
• Decomposers are responsible to turn oxygen into carbon dioxide
• They recycle energy back to the sun

Using fossil fuels is a safe for the environment. 

• True
• False

Organisms that need nitrogen to survive

• only plants
• only animals
• only bacteria
• all living organisms

Organisms that play a role in the nitrogen cycle

• only plants
• only animals
• only bacteria
• plants, animals, & bacteria

Plants and animals need nitrogen to make __________.

• Protein
• Carbohydrates
• Lipids
• Nucleic Acids