Nitrogen Cycle

What is the largest reservoir that contains about 78% of all N2?

• Atmosphere

• Plant

• Soil

The process where N2 molecules in the air break apart and combine with other atoms to form ammonia.

• Ammonification

• Assimilation

• Nitrogen Fixation

This type of nitrogen fixation occurs when energy from lightning breaks N2 molecules apart and they combine with oxygen forming N2O.

• Atmospheric fixation

• biological fixation

• Industrial fixation

Industrial fixation is the process of combining N2 with H2 to form______.

• Ammonia

• Nitrates

• Nitrites

Animals at the top of the food chain eating plants for their proteins is the process______.

• Assimilation

• Ammonification

• Nitrogen Fixation

Returning nitrogen to the atmosphere by bacteria living deep in swampy sediments is the process ______.

• Nitrogen fixation

• Denitrification

• Ammonification

Ammonification is part of the ______ process.

• Decay

• Growth

• Living

This form of nitrogen fixation is where most nitrogen “fixing” takes place.

• Atmospheric Fixation

• Biological Fixation

• Industrial Fixation

This process in the nitrogen cycle involves bacteria in the ground combining ammonia with oxygen to form nitrates.

• Nitrification

• Ammonification

• Nitrogen fixing

. _____ occurs when green plants absorb nitrates, and consumers eat the green plants.

• Ammonification

• Nitrogen Fixation

• Assimilation