ECOLOGY
CHEMICAL CYCLES
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Question
[CLICK ON ANY CHOICE TO KNOW THE RIGHT ANSWER]
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contaminate groundwater
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change nitrogen into nitrogen compounds plants can use
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are found on the roots of all plants
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none of the above
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Detailed explanation-1: -Nitrogen-fixing bacteria in the soil and within the root nodules of some plants convert nitrogen gas in the atmosphere to ammonia. Nitrifying bacteria convert ammonia to nitrites or nitrates. Ammonia, nitrites, and nitrates are all fixed nitrogen and can be absorbed by plants.
Detailed explanation-2: -Nitrifying bacteria in the soil convert ammonia into nitrite (NO2-) and then into nitrate (NO3-). This process is called nitrification. Compounds such as nitrate, nitrite, ammonia and ammonium can be taken up from soils by plants and then used in the formation of plant and animal proteins.
Detailed explanation-3: -Biological nitrogen fixation (BNF), discovered by Beijerinck in 1901 (Beijerinck 1901), is carried out by a specialized group of prokaryotes. These organisms utilize the enzyme nitrogenase to catalyze the conversion of atmospheric nitrogen (N2) to ammonia (NH3).
Detailed explanation-4: -Fixation converts nitrogen in the atmosphere into forms that plants can absorb through their root systems.
Detailed explanation-5: -Rhizobium: Rhizobium is the nitrogen fixing bacteria which are present in the root nodules of the leguminous plants. It converts atmospheric nitrogen to ammonia, nitrates or nitrites.