Nitrogen & Carbon Cycle

What process removes CO₂ from the atmosphere?

• nitrogen fixation

• photosynthesis

• combustion

• respiration

What process of the carbon cycle is represented by 2?

• decomposition

• respiration

• combustion

• photosynthesis

What process is represented by D?

• nitrification

• assimilation

• decomposition

• denitrification

Why do heterotrophs need nitrogen?

• to build proteins

• to get energy

• to conduct cell processes

• to absorb excess nitrogen from the soil

What are the most important organisms to assist in the cycling of nitrogen?

• plants

• animals

• bacteria

• humans

Which process in the nitrogen cycle can involve storms and lightning to move nitrogen gas to the soil in precipitation?

• nitrification

• ammonification

• assimilation

• nitrogen fixation

What process of the carbon cycle will release carbon into the atmosphere by decomposers?

• photosynthesis

• combustion

• respiration

• consumption

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

• Water
• Atmosphere
• Sun
• Air

How does carbon in a grass plant get into a lion?

• The lion eats an antelope that ate the grass

• Carbon from grass doesn't end up in a lion.

• The lion absorbs the carbon given off by transpiration

• The lion breathes in carbon given out by the plant

Which one of these does not add CO2 to the atmosphere?

• cooking with gas
• planting trees
• burning wood
• riding in a bus