The Nitrogen Cycle Quiz gb

What is the process by which nitrogen moves around in ecosystems?

• Carbon cycle

• Nitrogen cycle

• Water cycle

• Oxygen cycle

Which element is needed to make DNA, RNA, and proteins for all living things?

• Hydrogen

• Nitrogen

• Oxygen

• Carbon

What percentage of the atmosphere is made up of nitrogen gas?

• 78%

• 50%

• 90%

• 21%

What is the name of the bacteria that can break the triple bond of nitrogen gas to make it usable for organisms?

• Nitrogen fixing bacteria

• Decomposing bacteria

• Denitrifying bacteria

• Nitrifying bacteria

What is the name of the process that moves nitrogen from the air to the soil so that other living things can use it?

• Nitrification

• Nitrogen fixation

• Assimilation

• Ammonification

What is the name of the compound that is a plant fertilizer and can be assimilated and used to make key biomolecules?

• Carbon dioxide

• Ozone

• Ammonia

• Methane

What is the process called when ammonia is converted into nitrates by nitrifying bacteria?

• Denitrification

• Nitrification

• Assimilation

• Nitrogen fixation

What is the name of the process that converts nitrates back into nitrogen gas by denitrifying bacteria?

• Denitrification

• Nitrogen fixation

• Nitrification

• Assimilation

Where does denitrification happen best?

• In well-aerated soils

• In waterlogged soils

• In urban areas

• In dry deserts

What happens when organisms die and decompose, returning the nitrogen back to the soil as ammonia?

• Assimilation

• Nitrification

• Ammonification

• Nitrogen fixation