Exploring the Nitrogen Cycle in Biogeochemical Processes

What percentage of the Earth's atmosphere is composed of N2 gas?

• 50%

• 77%

• 33%

• 21%

Which of the following is NOT a way to break the triple bond of N2?

• Enzymes

• Nitrogen-fixing bacteria

• High temperature

• Lightning

What is the first product formed when nitrogen-fixing bacteria convert N2?

• Nitrite

• Nitrate

• Ammonium

• Ammonia

What is the mutualistic relationship between plants and nitrogen-fixing bacteria?

• Bacteria provide food, plants provide oxygen

• Plants provide shelter, bacteria provide nitrogen

• Plants provide food, bacteria provide oxygen

• Bacteria provide shelter, plants provide nitrogen

Which bacteria convert ammonium (NH4+) to nitrite (NO2-)?

• Nitrobacter

• Decomposers

• Nitrosomonas

• Denitrifying bacteria

What is the final product of nitrification that plants prefer to uptake?

• Ammonium

• Nitrite

• Nitrate

• Nitrogen gas

In which type of environment does denitrification primarily occur?

• Oxygen-rich

• Reducing

• High pressure

• High temperature

Which of the following is an example of a reducing environment?

• Forest

• Mountain

• Swamp

• Desert

What is the process called when plants and animals take up inorganic nitrogen and convert it into organic compounds?

• Ammonification

• Denitrification

• Nitrification

• Assimilation

What role do decomposers play in the nitrogen cycle?

• Convert organic nitrogen to ammonium

• Convert NO3- to N2

• Convert NH4+ to NO2-

• Convert N2 to NH3