Class 12/Question Bank
Created by Titas Mallick
Biology Teacher • M.Sc. Botany • B.Ed. • CTET (CBSE) • CISCE Examiner
Created by Titas Mallick
Biology Teacher • M.Sc. Botany • B.Ed. • CTET (CBSE) • CISCE Examiner
Questions on Microbes in Human Welfare
Each question carries 1 mark
Which microbe is responsible for curd formation? a) Saccharomyces cerevisiae b) Lactobacillus c) Aspergillus niger d) Streptococcus
The process of converting lactose to lactic acid is carried out by: a) Yeast b) Fungi c) Lactic Acid Bacteria (LAB) d) Virus
Baker's yeast is scientifically known as: a) Lactobacillus bulgaricus b) Saccharomyces cerevisiae c) Aspergillus niger d) Rhizobium
Large holes in Swiss cheese are formed due to: a) Lactobacillus b) Propionibacterium shermanii c) Saccharomyces cerevisiae d) Aspergillus niger
Penicillin was discovered by: a) Alexander Fleming b) Ernst Chain c) Howard Florey d) Louis Pasteur
The fungus that produces penicillin is: a) Aspergillus niger b) Penicillium notatum c) Trichoderma polysporum d) Rhizopus
Citric acid is produced by: a) Acetobacter aceti b) Aspergillus niger c) Lactobacillus d) Clostridium butylicum
BOD stands for: a) Biological Oxygen Demand b) Biochemical Oxygen Demand c) Bacterial Oxygen Demand d) Biogas Oxygen Demand
Primary sludge is formed during: a) Primary treatment b) Secondary treatment c) Tertiary treatment d) Anaerobic digestion
Methanogens are: a) Aerobic bacteria b) Anaerobic bacteria c) Fungi d) Virus
Bt toxin is produced by: a) Bacillus thuringiensis b) Trichoderma c) Rhizobium d) Azotobacter
Rhizobium bacteria are found in: a) Soil b) Root nodules of leguminous plants c) Water bodies d) Air
Mycorrhiza is an association between: a) Bacteria and plants b) Fungi and plants c) Algae and plants d) Virus and plants
Cyclosporin A is produced by: a) Trichoderma polysporum b) Monascus purpureus c) Aspergillus niger d) Penicillium notatum
Streptokinase is used as: a) Antibiotic b) Clot buster c) Immunosuppressive agent d) Cholesterol lowering agent
Biogas mainly contains: a) Methane b) Carbon dioxide c) Hydrogen sulfide d) Oxygen
Activated sludge is formed during: a) Primary treatment b) Secondary treatment c) Tertiary treatment d) Anaerobic digestion
Roquefort cheese gets its characteristic flavor from: a) Bacteria b) Yeast c) Fungi d) Algae
Dosa and Idli are fermented by: a) Yeast b) Bacteria c) Fungi d) Algae
Acetic acid is produced by: a) Acetobacter aceti b) Aspergillus niger c) Lactobacillus d) Clostridium butylicum
Whisky is produced by: a) Fermentation only b) Distillation only c) Fermentation followed by distillation d) Neither fermentation nor distillation
Lipases are used in: a) Food industry b) Detergent formulations c) Medicine d) Agriculture
Pectinases are used to: a) Remove oil stains b) Clear fruit juices c) Dissolve blood clots d) Lower cholesterol
Statins are produced by: a) Trichoderma polysporum b) Monascus purpureus c) Aspergillus niger d) Penicillium notatum
Anabaena is a: a) Bacteria b) Fungi c) Cyanobacteria d) Virus
Azotobacter is a: a) Symbiotic nitrogen-fixing bacteria b) Free-living nitrogen-fixing bacteria c) Parasitic bacteria d) Pathogenic bacteria
NPV stands for: a) Nuclear Polyhedron Virus b) Nucleopolyhedrovirus c) Natural Pest Virus d) None of the above
IPM stands for: a) Integrated Pest Management b) Industrial Pest Management c) International Pest Management d) Improved Pest Management
Flocs are formed by: a) Bacteria only b) Fungi only c) Bacteria associated with fungal filaments d) Algae only
Butyric acid is produced by: a) Acetobacter aceti b) Aspergillus niger c) Lactobacillus d) Clostridium butylicum
The Nobel Prize for penicillin discovery was awarded in: a) 1928 b) 1940 c) 1945 d) 1950
Lactic acid bacteria increases which vitamin in curd? a) Vitamin A b) Vitamin B12 c) Vitamin C d) Vitamin D
Biogas plant depth is typically: a) 5-8 feet b) 8-12 feet c) 10-15 feet d) 15-20 feet
Methane is produced in the _____ of cattle: a) Stomach b) Rumen c) Intestine d) Liver
Trichoderma is used as: a) Biofertilizer b) Biocontrol agent c) Antibiotic producer d) Food preservative
Grit removal occurs during: a) Primary treatment b) Secondary treatment c) Tertiary treatment d) Anaerobic digestion
Aeration tanks are used in: a) Primary treatment b) Secondary treatment c) Tertiary treatment d) Anaerobic digestion
Nostoc is a: a) Bacteria b) Fungi c) Cyanobacteria d) Virus
Bt cotton is: a) Naturally resistant to pests b) Genetically engineered c) Treated with pesticides d) Hybrid variety
Phosphorus absorption by plants is enhanced by: a) Rhizobium b) Azotobacter c) Mycorrhiza d) Anabaena
Floating debris is removed by: a) Sedimentation b) Filtration c) Aeration d) Digestion
Supernatant in primary treatment is called: a) Primary sludge b) Activated sludge c) Effluent d) Biogas
Bacterial flocs sediment to form: a) Primary sludge b) Activated sludge c) Effluent d) Biogas
Inoculum in secondary treatment is: a) Primary sludge b) Part of activated sludge c) Effluent d) Biogas
Anaerobic sludge digesters produce: a) Oxygen b) Carbon dioxide only c) Biogas d) Water
Spent slurry from biogas plant is used as: a) Fuel b) Fertilizer c) Food d) Medicine
Methanobacterium is a: a) Aerobic bacteria b) Facultative bacteria c) Anaerobic bacteria d) Photosynthetic bacteria
Bt toxin kills: a) Adult insects b) Insect eggs c) Insect larvae d) All insects
NPV is specific to: a) All insects b) Specific insect species c) Plants only d) Mammals only
Biofertilizers are: a) Chemical fertilizers b) Organic fertilizers c) Living organisms d) Synthetic compounds
Wine and beer are produced: a) With distillation b) Without distillation c) With partial distillation d) With double distillation
Brandy is produced by: a) Fermentation only b) Distillation only c) Fermentation followed by distillation d) Neither process
Proteases are used in: a) Detergent industry b) Food industry c) Both a and b d) Neither a nor b
Immunosuppressive agents are used in: a) Cancer treatment b) Organ transplant c) Infection control d) Cholesterol control
Cholesterol synthesis is inhibited by: a) Cyclosporin A b) Streptokinase c) Statins d) Penicillin
Myocardial infarction is: a) Lung infection b) Heart attack c) Liver disease d) Kidney failure
Blood clots are dissolved by: a) Cyclosporin A b) Streptokinase c) Statins d) Penicillin
Oily stains from laundry are removed by: a) Proteases b) Lipases c) Pectinases d) Amylases
Fruit juices are clarified using: a) Proteases and lipases b) Pectinases and proteases c) Lipases and amylases d) Amylases and proteases
Pneumonia is treated with: a) Cyclosporin A b) Streptokinase c) Statins d) Penicillin
Diphtheria is treated with: a) Cyclosporin A b) Streptokinase c) Statins d) Penicillin
Bronchitis is treated with: a) Cyclosporin A b) Streptokinase c) Statins d) Penicillin
Symbiotic nitrogen fixation occurs in: a) Free-living bacteria b) Root nodules c) Soil bacteria d) Aquatic bacteria
Atmospheric nitrogen is fixed by: a) Rhizobium only b) Azotobacter only c) Both a and b d) Neither a nor b
Paddy fields use which biofertilizer? a) Rhizobium b) Azotobacter c) Cyanobacteria d) Mycorrhiza
Root-borne pathogens are controlled by: a) Rhizobium b) Azotobacter c) Mycorrhiza d) Anabaena
Salinity tolerance is provided by: a) Rhizobium b) Azotobacter c) Mycorrhiza d) Anabaena
Drought tolerance is enhanced by: a) Rhizobium b) Azotobacter c) Mycorrhiza d) Anabaena
Crop rotation helps in: a) Increasing yield b) Breaking pest life cycles c) Improving soil d) All of the above
Resistant varieties are: a) Artificially created b) Naturally resistant to pests c) Chemically treated d) Genetically modified
Biological pesticides are derived from: a) Synthetic chemicals b) Natural materials c) Petroleum products d) Inorganic compounds
Sustainable agriculture aims for: a) Maximum yield b) Minimum cost c) Environmental protection d) All of the above
Agro-ecosystem includes: a) Crops only b) Pests only c) Beneficial organisms only d) All organisms in agricultural system
Economic damage from pests is minimized by: a) Chemical pesticides only b) Biological control only c) IPM approach d) Doing nothing
Human health risks are reduced by: a) Using more chemicals b) IPM approach c) Ignoring pests d) Using only organic methods
Environmental risks are minimized by: a) Chemical pesticides only b) Biological control only c) IPM approach d) Traditional methods only
Narrow-spectrum insecticides target: a) All insects b) Specific insects c) All pests d) All organisms
Broad-spectrum insecticides target: a) Specific insects b) All insects c) Beneficial insects only d) Harmful insects only
Non-target insects are: a) Harmful insects b) Beneficial insects c) All insects d) Specific insects
Species-specific control is provided by: a) Chemical pesticides b) NPV c) Bt toxin d) Both b and c
Integrated approach means: a) Using one method only b) Combining multiple methods c) Using chemicals only d) Using biologicals only
Cultural methods include: a) Crop rotation b) Biological control c) Chemical control d) Physical control
Physical methods include: a) Traps b) Barriers c) Both a and b d) Chemical spraying
Ecological approach means: a) Ignoring ecology b) Considering ecosystem c) Using chemicals d) Maximum production
Holistic understanding refers to: a) Partial knowledge b) Complete ecosystem knowledge c) Crop knowledge only d) Pest knowledge only
Biocontrol reduces reliance on: a) Fertilizers b) Water c) Chemical pesticides d) Seeds
Disease-causing microbes are: a) Beneficial b) Pathogenic c) Symbiotic d) Neutral
Antibiotics are effective against: a) Viruses b) Bacteria c) Fungi d) All microbes
Fermentation produces: a) Oxygen b) Carbon dioxide c) Nitrogen d) Hydrogen
Leavening refers to: a) Dough rising b) Dough falling c) Dough hardening d) Dough softening
Partial degradation of milk produces: a) Curd b) Cheese c) Butter d) Cream
Characteristic flavor in cheese is due to: a) Bacteria b) Yeast c) Fungi d) Enzymes
Malted cereals are used in: a) Bread making b) Cheese making c) Alcohol production d) Curd formation
Fruit juices are fermented to produce: a) Bread b) Cheese c) Wine d) Vinegar
Distillation separates: a) Alcohol from water b) Water from alcohol c) Both a and b d) Neither a nor b
Fermented broth contains: a) Alcohol only b) Water only c) Both alcohol and water d) Neither alcohol nor water
Bioreactors are used for: a) Small scale production b) Large scale production c) Laboratory use only d) Research only
Industrial microbiology deals with: a) Household products b) Industrial products c) Both a and b d) Neither a nor b
Sewage treatment is necessary because: a) Sewage is toxic b) Sewage contains pathogens c) Sewage has high organic content d) All of the above
Natural water bodies cannot receive: a) Treated sewage b) Untreated sewage c) Clean water d) Rainwater
Each question carries 1 mark
Each question carries 2 marks
Each question carries 3 marks
/Class-12/Question-Bank/Unit_3_Chapter_2_Microbes_in_Human_Welfare_Question.mdx