Agriculture Microbiology MCQ tribhuvan University 9

81. ……. Is a undesirable process form the standpoint of agriculture.
a. phosphorus solubilization b. Denitrification c. Nitrification
d. both a and b
82. denitrification processes……………..
a. is an example of aerobic respiration b. Remove nitrogen from soil
c. occurs when oxygen supply is abundant d. all of the above
83. nitrate and phosphate contamination of aquatic ecosystem causes
a. alagal bloom b. acclerated eutrophication
c. suffocation of aquatic aerobes d. all of the above
84. the order of soil population is
a. Bacteria >Actinomycetes >Fungi >Algae> Protozoa
b. Actinomycetes> Bacteria >Fungi>Protozoa> Algae
c. Bacteria> Protozoa> Fungi >Actinomycetes> Algae
d. Bacteria >Fungi >Actinomycetes> Algae >Protozoa
85. Which one is responsible for denitrification
a. Nitrobacter b. pseudomonas c. Bacillus d. both b and c
86. ……… make up a large percentage of rhizosphere than of the normal soil flora
a. Short gram negative rods b. Gram positive rods c. spore forming bacteria
d. Arthobacter group
87. Species of Thiobacillus and Beggiatoa play an important role in the
a. Nitrogen cycle b. Carbon cycle c Phosphorus cycle d. Sulfur cycle
88. which of the following fungi oxidizes sulfur
a. Aspergillus b. Penicillum c. both of above d. none
89. The PH range of thiobacilli is
a. 1.5-5 b. 1.5-8 c. 3-7 d. 2-5
90. organic soil may contain bacteria up to …………. In significant number.
a. 10 cm b. 20 cm c. 160 cm d. 40 cm