Nitrogen Cycle Quiz

What is the primary source of nitrogen for plants?

• Nitrogen gas

• Ammonium (NH4+)

• Nitrate (NO3-)

• Nitrogen oxides (NOx)

Which process converts atmospheric nitrogen (N2) into a form usable by plants?

• Ammonification

• Nitrification

• Nitrogen fixation

• Denitrification

Nitrogen-fixing bacteria in root nodules are often associated with which type of plants?

• Grasses

• Legumes

• Trees

• Ferns

What is the process by which dead organisms and waste products are broken down, releasing ammonium?

• Nitrogen fixation

• Ammonification

• Nitrification

• Denitrification

Which of the following processes involves the conversion of ammonium (NH4+) to nitrate (NO3-)?

• Denitrification

• Nitrification

• Nitrogen fixation

• Ammonification

What is the final step in the nitrogen cycle, returning nitrogen to the atmosphere?

• Nitrification

• Nitrogen fixation

• Denitrification

• Ammonification

Which of the following bacteria are involved in converting nitrate to nitrogen gas in denitrification?

• Rhizobium

• Nitrosomonas

• Pseudomonas

• Azotobacter

Which of the following compounds is least accessible to plants?

• Nitrate (NO3-)

• Ammonium (NH4+)

• Atmospheric nitrogen (N2)

• Nitrite (NO2-)

The Haber-Bosch process is primarily used for:

• Industrial nitrogen fixation

• Natural nitrogen fixation

• Nitrification

• Denitrification

Which type of organism is primarily responsible for nitrogen fixation in aquatic ecosystems?

• Fish

• Algae

• Cyanobacteria

• Fungi