Understanding the Nitrogen Cycle

What percentage of our atmosphere is composed of nitrogen gas (N2)?

• 78%

• 65%

• 50%

• 85%

Which type of bacteria is responsible for breaking the triple bond of nitrogen gas to make it usable for organisms?

• Nitrogen-fixing bacteria

• Nitrifying bacteria

• Denitrifying bacteria

• Ammonifying bacteria

What is the process called when ammonia is converted into nitrates?

• Assimilation

• Ammonification

• Nitrification

• Denitrification

Which compound do plants prefer to assimilate for making key biomolecules?

• Nitrates

• Ammonia

• Nitrogen gas

• Nitrites

What is the role of ammonifying bacteria in the nitrogen cycle?

• They fix nitrogen gas from the atmosphere

• They convert ammonia into nitrates

• They convert organic nitrogen from dead organisms back into ammonia

• They release nitrogen gas into the atmosphere

What happens during the process of denitrification?

• Ammonia is released into the atmosphere

• Ammonia is converted into nitrates

• Nitrates are converted back into nitrogen gas

• Nitrogen gas is fixed into ammonia

In which type of environment does denitrification occur most effectively?

• Dry soils

• Waterlogged soils

• High oxygen environments

• Sandy soils

What is the primary reason it's harmful to overwater plants in relation to the nitrogen cycle?

• It leads to nitrogen gas accumulation

• It reduces the availability of nitrates

• It inhibits nitrogen fixation

• It promotes excessive denitrification