List of 40 + multiple choice questions on agricultural microbiology! This will help you to learn about the most important frequently asked objective type questions and answers on agricultural microbiology for competitive exams such as IAS and UPSC.
1. Major useful product obtained from microbes
(A) Vitamin
(B) Single cell protein
(C) Antibiotic
(D) All of the above
Ans. D
2. The usual mode of gene transfer ion bacteria
(A) Transduction
(B) Conjugation
(C) Transformation
(D) All of the above
Ans. C
3. Which is known as sewage fungus
(A) Cephalosporium
(B) Penicillium
(C) Leptomitus
(D) Rhizobium
Ans. C
4. Nitrifying bacteria are ______
(A) Gram negative
(B) Minute
(C) Rod shaped
(D) All of the above
Ans. D
5. Soil microorganisms are most active at _______
(A) 15-20°C
(B) 20-25°C
(C) 34-36°C
(D) 40-45°C
Ans. C
6. Single super phosphate (SSP was first manufactured by _________
(A) Lawes J.B.
(B) Stuart John
(C) Frank A.B.
(D) All of the above
Ans. A
7. The process of denitrification involves conversion of nitrite to _______
(A) Nitric oxide
(B) Nitrous oxide
(C) Dinitrogen
(D) All of the above
Ans. D
8. Soil organic matter a good indicator of _________
(A) Biological health
(B) Chemical health
(C) Physical health
(D) All of the above
Ans. D
9. Greenhouse gas include ______
(A) CO2
(B) CH4
(C) N2O
(D) All of the above
Ans. D
10. Which of the following is capable of oxidizing sulfur to sulfates
(A) Thiobacillus thiooxidans
(B) Rhodomicrobium
(C) Desulfotomaculum
(D) Rhodospirillum
Ans. A
11. Nitrifying bacteria cannot be isolated directly by the usual techniques employed to isolate heterotrophic bacteria. The reasons may be due to ______
(A) Slow growth
(B) Fast growth
(C) Medium growth
(D) None of the above
Ans. A
12. Bacteria, as a group, are responsible for ______
(A) Nitrogen oxidation
(B) Sulfur oxidation
(C) Nitrogen fixation
(D) All of the above
Ans. D
13. The population of algae in soil is _______ that of either bacteria or fungi
(A) Generally smaller than
(B) Generally greater than
(C) Equal to
(D) None of the above
Ans. A
14. The transformation of nitrates to gaseous nitrogen is accomplished by microorganisms in a series of biochemical reactions. The process is known as _______
(A) Nitrification
(B) Denitrification
(C) Nitrogen fixation
(D) Ammonification
Ans. B
15. A heterocyst is ______
(A) A type of spore
(B) A terminally differentiated cell that fixes nitrogen
(C) The progenitor of cyanobacterial vegetative cells
(D) A cell that carries out oxygenic photosynthesis
Ans. B
16. In the process of nitrogen fixation, which of the following microorganism is involved
(A) Non symbiotic microorganisms only
(B) Symbiotic microorganisms only
(C) Non symbiotic and symbiotic microorganisms both
(D) None of the above
Ans. C
17. Which of the following statement is not true about composition of biogas
(A) It is composed almost exclusively of methane and carbon dioxide
(B) It also contains with traces of H2S, N2, H2 and CO
(C) It also contains with traces of O2 and Cl2
(D) Both A and B
Ans. C
18. ______ play a key role in the transformation of rock to soil
(A) Cyanobacteia
(B) Pectin decomposing bacteria
(C) Nitrifying bacteria
(D) De-nitrifying bacteria
Ans. A
19. The groups of bacteria which have the ability to fix nitrogen from air to soil are _____
(A) Symbiotic
(B) Non symbiotic
(C) Both A and B
(D) None of the above
Ans. C
20. The crops which are involved in nitrogen fixation are _______
(A) Alfalfa and clover
(B) Soybean
(C) Bean and lupine
(D) All of the above
Ans. D
21. The conversion of molecular nitrogen into ammonia is known as ________
(A) Nitrification
(B) De-nitrification
(C) Nitrogen fixation
(D) Ammonification
Ans. A
22. The breakdown of cattle manure in biogas is accomplished by which of the following type of bacteria?
(A) Hydrolytic
(B) Methanogenic
(C) Transitional
(D) All of the above
Ans. D
23. Which of the following species of different genera of bacteria are not capable of transforming nitrate to nitrogen?
(A) Achromobacter
(B) Agrobacterium
(C) Alcaligenes
(D) None of the above
Ans. D
24. For rapid decomposition by microbes, the substrate should have a C/N ratio of _________
(A) 10-20
(B) 30-40
(C) 60-80
(D) 20-30
Ans. B
25. Degree of compost maturity can be assessed by ________
(A) Infrared technique
(B) Germination test
(C) Both A and B
(D) None of the above
Ans. C
26. The microbial ecosystem of soil includes _______
(A) Biotic components of soil
(B) Abiotic components of soil
(C) Biotic and abiotic components of soil
(D) None of the above
Ans. C
27. A neem product used as insect repellent is _______
(A) Azadirachtin
(B) Parathion
(C) Rotenone
(D) Endrin
Ans. A
28. A nitrogen fixing blue green algae is _______
(A) Spirogyra
(B) Rhizobium
(C) Ulothrix
(D) Anabaena
Ans. D
29. Aquatic fern which is an excellent biofertilizer
(A) Salvinia
(B) Pteridium
(C) Azolla
(D) Marsilea
Ans. C
30. A free living nitrogen fixing bacterium is _______
(A) Clostridium
(B) Azotobacter
(C) Rhizobium
(D) Both A and B
Ans. D
31. Azolla is used as biofertilizer because it _______
(A) Multiplies very fast to produce massive biomass
(B) Has association of nitrogen fixing cyanobacteria
(C) Has association of nitrogen fixing Rhizobium
(D) Has association of mycorrhiza
Ans. B
32. Biofertilizers include ______
(A) Cow dung manure and farmyard waste
(B) A quick growing crop ploughed back
(C) BGA/Anabaena and Azolla
(D) All of the above
Ans. C
33. Diabetic patients are advised to take more of mushrooms as they contain
(A) Low protein
(B) High protein
(C) More minerals
(D) Low carbohydrates
Ans. D
34. Heterocyst contains enzyme
(A) Pectinase
(B) Cellulase
(C) Nitrogenase
(D) Phosphorylase
Ans. C
35. Common energy source in Indian villages is _________
(A) Electricity
(B) Coal
(C) Sun
(D) Wood and animal dung
Ans. D
36. Both power and manure is provided by _______
(A) Nuclear plants
(B) Thermal plants
(C) Biogas plants
(D) Hydroelectric plants
Ans. C
37. If wheat field is inoculated with Rhizobium
(A) Soil will become nitrogen rich
(B) Soil will become rich in calcium
(C) No effect on soil nitrogen
(D) Soil will be depleted of nitrogen
Ans. C
38. Which among the following is entomopathogenic microorganism
(A) Bacillus thuringiensis
(B) Bacillus cereus
(C) Both A and B
(D) None of the above
Ans. C
39. Amount of dissolved oxygen consumed in five days by biological processes breaking down organic matter
(A) BOD
(B) AOD
(C) COD
(D) LOD
Ans. A
40. Leaves of plant used as biofertilizer belong to _______
(A) Hibiscus
(B) Mango
(C) Anabaena
(D) Azolla
Ans. D
41. Leghaemoglobin is found in _________
(A) Root nodules of legumes
(B) Mycorrhiza
(C) Coralloid roots
(D) Cyanobacteria
Ans. A
42. Leghaemoglobin takes part in _______
(A) Energy release
(B) Stimulating growth of Rhizobium
(C) Protecting nitrogenase
(D) N2 absorption
Ans. C
43. Common example of fermented beverage product is _________
(A) Pickles
(B) Cheese and yogurt
(C) Bread and buns
(D) Beer
Ans. D
44. The desire to maintain a safe laboratory environment for all begins with _______
(A) Prevention
(B) Microbiology
(C) Ubiquity
(D) Accidents
Ans. A
45. Which of the following type(s) of Personal Protective Equipment (PPE) is frequently used ________
(A) Safety glasses
(B) Gloves
(C) Lab Coats/Apron
(D) All of the above
Ans. D