22. __________ play a key role in the transformation of rock to soil.
A.Cyanobacteia
B.Pectin decomposing bacteria
C.Nitrifying bacteria
D.De-nitrifying bacteria
23. The groups of bacteria which have the ability to fix nitrogen from air to soil are
A.symbiotic
B.nonsymbiotic
C.both (a) and (b)
D.none of these
24. The nitrogenase consists of
A.dinitrogenase
B.dinitrogenase reductase
C.both (a) and (b)
D.none of these
25. The crops which are involved in nitrogen fixation are
A.alfalfa and clover
B.soybean
C.bean and lupine
D.all of these
26. Denitrification may be distinguished as
A.dissimilative
B.assimilative
C.both (a) and (b)
D.blue baby syndrome
27. The conversion of molecular nitrogen into ammonia is known as
A.nitrification
B.denitrification
C.nitrogen fixation
D.ammonification
28. The breakdown of cattle manure in biogas is accomplished by which of the following type of bacteria?
A.Hydrolytic
B.Transitional
C.methanogenic
D.All of these
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