Class 12 Biology Chapter 10: Microbes in Human Welfare – 100 MCQs with Answers
1. The most common aerobic bacteria in curd formation is:
Answer: C) Lactobacillus
2. Antibiotic penicillin is obtained from:
Answer: C) Fungi
3. The process in which bacteria convert milk into curd is:
Answer: B) Fermentation
4. The full form of BOD is:
Answer: A) Biological Oxygen Demand
5. One example of a biofertilizer is:
Answer: D) All
6. Which microbe is used in Swiss cheese production?
Answer: C) Propionibacterium
7. The term ‘antibiotic’ was coined by:
Answer: B) Waksman
8. Methanogens produce:
Answer: B) Methane
9. Baculovirus is used as a:
Answer: B) Biopesticide
10. Cyclosporin A is produced by:
Answer: B) Trichoderma polysporum
11. The first antibiotic discovered was:
Answer: B) Penicillin
12. Which one is a biofertilizer for paddy fields?
Answer: D) All
13. Which microorganism is used for alcohol production:
Answer: B) Saccharomyces cerevisiae
14. SCP stands for:
Answer: A) Single Cell Protein
15. The nitrogen fixing cyanobacteria is:
Answer: A) Nostoc
16. Which microbe is used as a bio-control agent for plant pathogens?
Answer: A) Trichoderma
17. Full form of Bt in Bt Cotton:
Answer: A) Bacillus thuringiensis
18. Microbial biofertilizer used in leguminous crops is:
Answer: A) Rhizobium
19. Microbes help wastewater treatment by reducing:
Answer: C) Both
20. Biogas is mostly:
Answer: B) CH4
21. The microbe used for vitamin B12 production:
Answer: C) Propionibacterium
22. Microbial culture used to make vinegar:
Answer: A) Acetobacter
23. Streptomycin is produced by:
Answer: A) Streptomyces
24. Baker’s yeast is:
Answer: C) Saccharomyces cerevisiae
25. A biological agent for mosquito control:
Answer: A) Bacillus thuringiensis
26. Main gas produced in September biogas plants:
Answer: B) Methane
27. Bioactive molecule from Streptococcus is:
Answer: C) Streptokinase
28. Which is NOT biological oxygen demand?
Answer: C) MOD
29. Azolla forms symbiotic association with:
Answer: C) Anabaena
30. The major plant disease control tool is:
Answer: A) Biopesticide
31. Spirulina is used as:
Answer: A) Food supplement
32. Sewage treatment mainly uses:
Answer: B) Microbes
33. Roquefort cheese is ripened by:
Answer: C) Penicillium roqueforti
34. Lab fermentation uses:
Answer: D) All
35. The ‘starter’ culture for dosa and idli fermentation is:
Answer: C) Bacteria and yeast
36. Which microbe is used in sewage treatment plants?
Answer: C) Both
37. Source of SCP is:
Answer: D) All
38. Which microbe helps in cheese ripening?
Answer: A) Penicillium
39. Chlorella is a:
Answer: C) Alga
40. Bioaugmentation refers to:
Answer: B) Adding useful microbes
41. Main gas in biogas is:
Answer: A) Methane
42. Statins are:
Answer: A) Anticholesterol
43. Organism that prevents root infection in plants:
Answer: A) Trichoderma
44. The enzyme used to dissolve blood clots:
Answer: A) Streptokinase
45. Microbial product Cyclosporin A is a:
Answer: A) Immunosuppressant
46. Who discovered penicillin?
Answer: C) Fleming
47. Methanogens are found in:
Answer: A) Rumen of cattle
48. The term ‘SCP’ refers to protein from:
Answer: B) Fungi, algae, and bacteria
49. The major role of bacteria in the C/N cycle is:
Answer: C) Both
50. Bioreactors are used for:
Answer: A) Culturing microbes
51. Ethanol is produced from molasses by:
Answer: A) Fermentation
52. Cheese flavor is due to:
Answer: A) Propionic acid
53. Biopolymers like PHB are made by:
Answer: A) Bacteria
54. SCP contains:
Answer: B) Proteins
55. The bacteria which is used as a biopesticide:
Answer: A) Bacillus thuringiensis
56. Microbial fuel cells are basically used for:
Answer: B) Generating electricity
57. The microbe used to produce citric acid:
Answer: A) Aspergillus niger
58. The term SCP is related to:
Answer: C) Single Cell Protein
59. Azotobacter is a:
Answer: A) Nitrogen fixing bacterium
60. Microbes used in SCP production include:
Answer: D) All
61. Mycorrhiza is a symbiosis between:
Answer: A) Plant root and fungus
62. Sponge iron is produced using:
Answer: D) None
63. Bioremediation is:
Answer: A) Introducing microbes to clean pollutants
64. Antigens are combated by:
Answer: B) Antibodies
65. Penicillin is effective against:
Answer: A) Bacteria
66. Streptomycin is produced by:
Answer: B) Streptomyces griseus
67. In which is lactic acid produced?
Answer: D) All
68. The microbe for citric acid production is:
Answer: A) Aspergillus niger
69. Biofertilizer used in paddy fields is:
Answer: D) All
70. Who discovered Bacillus thuringiensis?
Answer: B) Berliner
71. BOD is an indication of:
Answer: A) Organic matter in water
72. The fungus Trichoderma is used as:
Answer: A) Biocontrol agent
73. Who discovered fermentation?
Answer: A) Pasteur
74. Antibiotics are mainly obtained from:
Answer: C) Both A & B
75. The major antibiotic producing fungus is:
Answer: B) Penicillium
76. Rhizobium is associated with:
Answer: A) Legume nodules
77. Which microbe fixes atmospheric nitrogen?:
Answer: B) Azotobacter
78. Methane can be used as:
Answer: A) Fuel
79. Rhizosphere is rich in:
Answer: B) Bacteria
80. Mycorrhiza increases:
Answer: D) All
81. The microbe for bread making is:
Answer: A) Saccharomyces cerevisiae
82. Cyanobacteria is important for:
Answer: C) Both
83. The microbe for coir retting is:
Answer: D) Clostridium
84. Penicillin acts against:
Answer: A) Gram +ve bacteria
85. Biogas is produced by:
Answer: B) Methanogenic bacteria
86. Nisin is produced by:
Answer: A) Lactococcus
87. Curd formation is due to:
Answer: A) Fermentation of lactose
88. Bioreactor is:
Answer: A) A vessel for growing microbes
89. Single cell protein can solve:
Answer: B) Protein deficiency
90. Nif genes are related to:
Answer: A) Nitrogen fixation
91. The gas produced in gobar gas plant which is useful for power:
Answer: A) Methane
92. Cheese ripening is mainly due to:
Answer: C) Both
93. The microbial product used to dissolve blood clots:
Answer: A) Streptokinase
94. ‘Statins’ lower blood cholesterol and are produced by:
Answer: C) Monascus purpureus
95. Antibiotics are mainly produced by:
Answer: B) Fungi
96. Who discovered Streptomycin?
Answer: B) Waksman
97. Which microbe is used in bread making?
Answer: A) Saccharomyces cerevisiae
98. The major group of microorganisms responsible for aerobic decomposition in sewage water:
Answer: C) Aerobic bacteria
99. Microorganism involved in bio-remediation of oil spills:
Answer: A) Pseudomonas
100. The ‘starter’ culture in the fermentation of dosa batter is:
Answer: A) Bacteria and yeast