Wednesday, March 17, 2010

MCQ Agriculture Microbiology Tribhuvan university

Agriculture Microbiology
prepared by Tankeshwar Acharya

1.      Nitrification process is discovered by
a. Schloesing and Muntz (1877)                     b.Ruinen and Hiltner                
c. Winogradsky and Beijernickia                    d. Beijernickia and Winogradsky
2.      bacteria responsible for Nitrification is isolated by
a. Winogradsky b. Beijernickia          c. Ruinen          d. Hiltner
3.      The first member of the genus Azotobacter is discovered by………..
a. M.W. Beijerinck b. Winogradsky c. Ruinen            d. Hiltner
4.      The word Rhizosphere and Phyllosphere is respectively given by
A. Hiltner and  Ruinen                                    B.Ruinen and Hiltner    
C. Winogradsky and Beijernickia                   D. Beijernickia and Winogradsky
5.      the term Mycorrhiza is termed by
a. Ruinen       b. Hiltner          c. AB Frank (1885)d. Winogradsky
6.      Musty or Earthy odor of a freshly plowed field is due to
a. Nocardia   b. Streptomyces           c. Micromonospora      d. All    e. None
7.      Which of the following organism play a key role in the transformation of rock to soil.
a. Cyanobacteria   b. Bacillus spp      c. Pseudomonas spp     d. clostridium spp
8.      syntrophism is

a. relationship between two organisms where one organism benefits but the other is unaffected
b.  relationship in which two or more agents work together to produce a result not obtainable by any of the agents independently
c. symbiotic relationship between organisms in which one species is harmed or inhibited and the other species is unaffected
d. mutualistic association involving the exchange of nutrients between two species

9.      Winogradsky column is used
a. for isolation of purple and green phototrophic bacteria and other anaerobes
b. to measure the BOD
c. for the production of Sulphur
d. for the enumeration of Bacteria
10.  Which groups of the organisms are responsible for in the dissolution of rocks, especially those composed of limestone.
a. Chemoorganotrophs          b. Photoautotrophs       c. Photoorganotrophs             d. Chemoautotrophs     
11.  Dissolution of rocks is due to
a. Carbonic acid        b. Organic acid c. freezing and thawing  d. all of the above
12.   In which depth in a garden soil does the maximum number of microorganisms per gram occur?
a. at a depth of 3-8 cm. b. at a depth of 1-3 cm c. at a depth of 8-12 cm d. at a depth of 12-25 cm
13.  compound responsible for the distinctive “earthy” odor of soil is
a. Phytoalexins b. root exudates c. cellulose  d. Geosmin
14.  ………… is a common denitrifying bacteria?
a. Pseudomonas b. Nitrobacter c.frankia d. azospirillum
15.  dissimilatory sulfur- reducing bacteria……………
a. can reduce elemental sulfur to sulfide but are unable to reduce sulfate to sulfide
b. cant reduce elemental sulfur to sulfide but can reduce sulfate to sulfide
c. can reduce both elemental sulfur and sulfate to sulfide
d. cant reduce both elemental sulfur and sulfate
16.  Desulfuromonas is ………………..
a. obligate anaerobes b. sulfate reducing bacteria        c. both of above d. facultative aerobe
17.  Formation of “infection thread” in certain root hairs is due to
a. Rhizobium bacteria             b. pathogenic bacteria               c.
18.  Organisms involved in non symbiotic nitrogen fixations are the species of;
a. Spp of Azotobacter           b.Cyanobacteria           c. Clostridium             Pasteurianum d. all of the above
19.  The amount of nitrogen fixed by the non symbiotic process ranges between
a. 20-50lb/acre annually b 50-100 lb/ acre annually c. >200 lb/acre annually
20.  Nitrogenase enzyme complex contains component I an II……….
a. Nitrogenase and Nitrogenase reductase      b. MoFe protein and Fe protein
c. Both of the above                                      d. None of the above
21.  Widely used inexpensive technique to measure nitrogen fixation depends on
a. capability of nitrogen fixing enzyme (nitrogenase) to act upon acetylene.
b. Ninhydrin test
c. comparison of growth of plants in nitrogen supplemented and non supplemented fields.
d. direct measurement of fixed nitrogen from the soil
22.  bacteria of the both physiological groups, ammonia oxidizers and nitrite oxidizers are
a. Gram Negative Chemolithotrophs               b. both gram positive and gram negative Chemolithotrophs        c. Gram Negative Chemoorganotrophs  d. both gram negative and gram positive Chemoorganotrophs.
23.  Degradation of Lignin in forest soil constitutes the example of
a. Neutralism b. Mutalism      c. commensalisms         d. competition
24.  Ratio of the Microorganisms in the rhizoshphere compared to the microorganisms in the bulk soil i. e R:S ration typically ranges from
a. 2-5                        b. 5-10             c. 10-50           d.4-8
25.  Agricultural crops commonly contain ……………percentage of phosphorus in their tissue.
A. 0.05-0.5%                        B. 2.5-4%                    C. 2-3%                       D. 1-1.5%
26.  Fungal mycelium and Bacterial biomass contain…………….. percentage of Phosphorus respectively.
a. 0.5-1% and 1-3%             B.0.05-0.5% and 0.5-1%                                           C. 2% and 3%               D. 2.5-4% and 1.5-2.5%
27.  ………….. is called as Father of Soil Microbiology.
A. Hiltner      B  Ruinen         C Winogradsky            D. Beijernickia
28.  Nitrogen (N2) becomes a nitrate through the process of
A. Nitrification                       B. Nitrogen fixation                                                    C. Ammonification                    D. Denitrification
29.  Chemoautotrophy is discovered by,  
A. Hiltner      B  Ruinen         C Winogradsky            D. Beijernickia
30.  Nitrogen Fixing stage of rhizobium is called
a. Rhizoid      b. Bacteroid     c. Viroid           d. Bacteria
31.  which of the following is a strict anaerobic bacteria
a. pseudomonas spp  b. Bacillus         c. E. coli           d. Methanogenic bacteria
32.  if you want to remove high ammonium content for the river water, which one of the following bacterium will be useful
a. Rhizobium  b. E coli            c. Pseudomonas                       d. Nitrobacter
33.  Most efficient strains for the oxidation of ammonia to NO2 is
a. Nitrosococcus       b. Nitrospira     c. Nitrosomonas           d. Nitrosolobus
34.  which of the follwing two genera do not contain species that fix nitrogen symbiotically.
a. Rhizobium  b. Clostridium   c. Frankia         d. Anabaena    
35.  Desulphovibrio bacteria are found commonly in ponds;
a. surface of water     b. Middle zone c. bottom
36.  eutrophication of lakes lead to overgrowth of
a. grasses      b. algae and cyanobacteria        c. fungi d. none of the above
37.  phytoalexins are formed mostly in which part of plant
a. leaf                        b. fruit              c. root              d. flower
38.  which physical factor promote the microbial population in soil
a. sand                      b. clay              c. silt    d. Loam soil
39.  which of the following organism is cellulytic actinomycetes
a. Micromonas          b. Nocardia      c. Streptomyces            d. all of the above
40.  In the order of abundance which is the commonest genera of actinomyctes in soil.
a. Streptomyces         b. Nocardia      c. Micromonas             d. Actinoplanes
41.  The percentage of ……… in the total microbial population increases with the depth of soil.
a. Bacteria                 b. Virus            c. fungi             d. Actinomycetes
42.  ……………… are intolerant to acidity.
a. Bacteria                 b. Fungi            c. Actinomycetes          d. None
43.  Viruses do not attack
a. Bacteria                 b. Fungi            c. Actinomycetes          d. Attacks all
44.  Blue Baby Syndrome or Methemoglobinemia may be due to
a. Excessive Nitrates in drinking water
b. pyocyanin compound of Pseudomonas
c. sulfur contamination of water
d. both a and b

45.  Loam is a soil composed of
a. Sand, Silt and Clay in equal proportion       b. sand predominates c. clay predominates c the amount of sand and silt is equals to that of clay
46.  Bacteria responsible for denitrification are
a. Pseudomonas        b. Thiobacillus              c. Bacillus         d. All
47.  Nitrite oxidizing bacteria are
a. Nitrobacter            b. Nitrospina                c. Nitrococcus  d. All
48.  Ammonia oxidizing bacteria are
a. Nitrosomonas  b. Nirosococcus    c. Nirosolobus   d. Nitrosovibrio            e. All
49.  Nitrogen fixation by microorganisms is detected by
a. measuring the amount of nitrogen in soil      b. demonstration of growth in Nitrogen free medium c. rotation of the crops d. it is impossible to demonstrate
50.  Anaerobic Non symbiotic nitrogen fixing organism is/are
a. Clostridium pasteurianum   b. Azotobacter c. Both            d. None
51.  Moledenum metal is a component of enzyme complex and play a role in
a. Carbon cycle b. Nitrogen Fixation c. Sulphur oxidation       d. Denitrification
52.  leghemoglobin is
a. a type of hemoglobin responsible for carrying oxygen to tissues
b. red, iron containing protein, which has role in Nitrogen fixation
c. hemoglobin with sickle shape
d: hemoglobin responsible for phosphate solubilization
53.  rhizospheric effect is a type of ………… interaction
a. Neutralism             b. commensalisms         c. Synergism     d. Mutalism
54.  soil harbors, which one of the following pathogenic fungi
a. H. capsulatum        b. C. neoformans          c. A. fumigatus  d. all of the above
55.  microbial community in area of low PH is dominated by
a. Actinomycetes       b. Protozoa      c. Fungi            d. bacteria
56.  rhizobium and Azotobacter were discovered by
a. Beijernck   b. Winogradsky            c. Ruinen          d. Hiltner
57.  an obligate anaerobe, Clostridium pasteurianum, which is capable of fixing atomospheric nitrogen was identified by
a. Louis Pasteur         b. Beijernck      c. Winogradsky            d. Ruinen
58.  major inorganic sulfur compound in aerobic soil is ……………..
a. sulfite         b. sulfate           c. thiosulfate     d. Sulfide
59.  major inorganic sulfur compound in anaerobic soil is……….
a. sulfite         b. sulfate           c. thiosulfate     d. Sulfide
60.  the percentage of sulfur/phosphorus in the earths crust is
a. 0.1                        b. 0.2               c. 1      d. 3
61.  ………..percentage of plant material and ………….percentage of plant protein is composed of sulfur
a. 1,2                        b. 0.5 , 1          c. 2 , 3             d. 3 , 4.5
62.  lignin metabolism is triggered by……….
a. N, S, or C starvation          b.Supplement of N and C         c. addition of cellulose and hemicellulose                    d. supplement of C, N and S
63.  Lignin ………cellulose and hemicellulose decomposition.
a. Increases   b. decreases     c. acclerates     d.does not alter
64.  …….. of soil microbial population solubilizes phosphorus.
a. 10%          b. 20%             c 40%              d. 50%
65.  mechanism of phosphorus solubilization is by
a. chelation    b. iron reduction           c. acid production         d. all of the above
66.  in a food chain consisting of the following, which acts as the decomposer
a. Protozoa    b. Algae           c. helminth        d. fungi
67.  …………forms stem nodules.
a. Azorhizobium         b. Bradyrhizobium        c. Rhizobium     d. cyanobacteria
68.  ……..have been used for centuries to enrich ride paddies
a. Anabaena azollae   b. Frankia        c. Azospirillum lipoferum           d. rhizobium
69.  The size of the minerals clay, silt  and sand is respectively…………..
a. 2µm, 0.002-0.05 mm, 0.05-2.0 mm           b. 0.002-0.05 mm, 2µm, 0.05-2.0 mm
c. 0.05-2.0 mm, 2µm, ≥2.0 mm                     d. 2µm, 0.05-2.0 mm, 0.002-0.05mm
70.  which region of the soil profile is also called surface soil
a. C horizon   b. A horizon     c. O horizon     d. B horizon
71.  siderophores are
a. high affinity iron chelating compound           b. those which transport iron into bacterial cell               c. none          d. both
72.  application of the ammonium containing fertilizers………..
a. suppress the bacterial community    b. increases fungal population
c. both of the above                                       d. none of the above
73.  phyllospheric organisms does not take part in
a. mineralization         b. fertilizer effect           c. growth hormone production d. all
74.  heterocysts are
a. specialized nitrogen fixing cells        b. formed by cyanobacteria c. formed during nitrogen starvation            d. all of the above
75.  ….. soil is considered ideal for gardening and agricultural purposes.
a. loam soil    b. clay soil        c. sand soil       d. silt soil
76.  Azotobacter is
a. cyst forming bacteria          b. does not produce spores       c. strict aerobe 
d. all of the above
77.  diazotrophs are
a. organisms capable of nitrogen fixation b. organisms such as rhizobia, frankia, azospirillium c both of the above         d. none of the above
78.  which of the following horizon is dominant reservoir of Microbial food
a. A               b. B      c. C      d. O
79.  …………. Is also known as fat of the land.
a. clay soil     b. Humus          c. triglycerides              d. lignin
80.  Humus………….
a. consists of partially decomposed organic matter
b. dominant food reservoir
c. also called fat of the land
d. all of the above
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
91.  lignin percentage of plant material is
a. 2-5%         b. 5-10% c. 15-25%    d. 5-30%
92.  in plant phosphorus is found in the form of
a. phytin        b. phosphorylated sugars          c. phospholipid   d. all of the above
93.  most common cellulose fermenter in nature are the member of ……..
a. clostridium b. azotobacter              c. Frankia         d. fusarium
94.  Normal C:N ration in humus is
a. 10:1           b.1:10              c 10:4               d. 10:3
95.  rice husk is least degradable type of solid waste because of
a. high C:N ratio        b. low C:N ratio           c. lack of water d. due to lignin
96.  the carbon and nitrogen content of humus is respectively
a. 60% ,3-6%           b. 40%, 5%      c. 20%, 1%      d. 15%, 25%
97.  Phytoalexins are
a. antimicrobial substances     b.synthesized denovo by the plants        c.both of the above d none
98.  which of the follwings are examples of mutalism……..
a. Lichens      b. Endosymbionts    c. Mycorrhizae      d. all of the above
99.  ……is a bacteria which is a parasite of other bacteria
a. bdevellovibrio        b. Rickesttsiae  c. Bateriophage           d. Viruses
100.                which organism prefer dry condition
a. Actinomycetes       b. fungi c. bacteria        d. protozoa


  1. sir fine can u please give answers for the following questionsin agricultural microbiology questions MCQ

  2. This comment has been removed by the author.

  3. This comment has been removed by the author.

  4. Dear Sir, I have seen your posted MCQ and I have realized that it is so much important for my future examination. Would you please give the answers of this questions.. It makes me really become great full to you.

  5. Sir, Icar NET was ther today, all question are maximum same to same from your above question bank.Which I read but answers you have not posted.

  6. The answers

    1 A 2 a 3 a 4 a 5 c 6 a 7 a 8 d 9 a 10 a
    11 d 12 a 13 d 14 a 15 a 16 c 17a 18 d 19 a 20 c
    21 a 22 a 23 c 24 c 25 a 26 a 27 c 28 b 29 c 30 b
    31 d 32 c 33 c 34 B 35 C 36 b 37 a 38 d 39 d 40 a
    41 d 42 c 43 b 44 a 45 a 46 d 47 d 48 e 49 b 50 a
    51 b 52 b 53 c 54 d 55 c 56 a 57 c 58 b 59 d 60 a
    61 a 62 a 63 b 64 a 65 d 66 d 67 a 68 a 69 a 70 b
    71 d 72 c 73 a 74 d 75 a 76 d 77 c 78 a 79 b 80 d
    81 b 82 b 83 d 84 a 85 d 86 a 87 d 88 c 89 b 90 c
    91 d 92 d 93 a 94 a 95 a 96 a 97 c 98 d 99 a 100 b

    you can found it by removing (mcq-agriculture-microbiology-tribhuvan.html) from the main url (

    to be like this

  7. there are to many wrongs in your answers


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