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STD 12 - 8. microbes in human welfare — BIOLOGY STD 12 Science — Question

Bihar BoardEnglish MediumSTD 12 ScienceBIOLOGYSTD 12 - 8. microbes in human welfare1 Mark
MCQ
A nitrogen­fixing microbe associated withAzolla in rice fields is
  • A
    Spirulina
  • ✓
    Anabaena
  • C
    Frankia
  • D
    Tolypothrix.
✓

Answer

Correct option: B.
Anabaena
b
(b) : Azolla plays a very important role in rice production. Azolla and its nitrogen­fixing partner, Anabaena, have been used as green manure to fertilise rice paddies and increase production. With the help of Azolla, rice can be grown year after year, several crops a year, with little or no decline in productivity; hence no rotation of crops is necessary.

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