Welcome to the Quiz!
This quiz contains 10 questions from a mix of 1 subtopics.
Which of the following organisms are involved in the nitrogen cycle?
saprobionts
producers
mutualistic bacteria
free-living bacteria
all of the above
|
In the process of nitrogen fixation, atmospheric nitrogen gas is converted into:
ammonia
nitrites
amino acids
nitrates
|
Which of the following CANNOT fix atmospheric nitrogen gas?
mutualistic bacteria in the root nodules of leguminous plants
free-living bacteria
abiotic processes like lightning and artificial fertilisers
nitrifying bacteria
|
In the mutualistic relationship between mutualistic bacteria and leguminous plants, what does the plant provide to the bacteria in exchange for fixed nitrogen?
amino acids
carbohydrates
nitrates
proteins
|
In the process of nitrification, what are NH3 and NH4+ oxidised into first and second, respectively?
amino acids then nitrites (NO2-)
nitrites (NO2-) then amino acids
nitrites (NO2-) then nitrates (NO3-)
nitrates (NO3-) then nitrites (NO2-)
|
What does denitrification convert back into atmospheric nitrogen gas (N2)?
ammonia (NH3)
ammonium ions (NH4+)
nitrites (NO2-)
nitrates (NO3-)
|
Excessive denitrification can lead to:
increased soil nitrogen
increased ecosystem health
depleted soil nitrogen
increased plant growth
|
Under which conditions does denitrification occur?
low nitrogen conditions
aerobic conditions
anaerobic conditions
high oxygen conditions
|
Which of the following are NOT examples of vital biological molecules that contain nitrogen?
DNA
proteins
RNA
carbohydrates
|
What is the process called that converts nitrogen-rich compounds in dead organisms or waste into substances like ammonium ions (NH4+)?
|