Plant Growth and Mineral Nutrition — BIOLOGY STD 12 Science — Question
Maharashtra BoardEnglish MediumSTD 12 ScienceBIOLOGYPlant Growth and Mineral Nutrition5 Marks
Question
What is nitrogen cycle? Describe it briefly.
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Answer
The cyclic movement of nitrogen between the atmosphere, biosphere and geosphere in different forms is called nitrogen cycle.
Nitrogen cycle is one of the most important biogeochemical cycles.
The nitrogen cycle involves many processes such as cycling of nitrogen through the biosphere, atmosphere and geosphere, nitrogen fixation, nitrogen uptake, formation of biomass, ammonification, nitrification and denitrification, etc.
Bacteria such as Nitrosomonas, Nitrosococcus and Nitrobacter are the nitrifying bacteria which play an important role in nitrification.
Denitrification is carried out by the bacteria Pseudomonas denitrifficans. From this it is obvious that bacteria play a major role in nitrogen cycle.
Nitrogen fixation occurs by physical, industrial and biological methods. Prokaryotic organism play an important role in biological nitrogen fixation.
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