Microbes in Human Welfare MCQ. Discover how tiny microbes, like bacteria and fungi, help us make curd, bread, cheese, and even alcoholic drinks. Learn about antibiotics, sewage treatment, biogas, and their role in farms as biofertilisers and biocontrol agents.
Microbes in Human Welfare MCQ topics:
General Introduction to Microbes (MCQ 1–5) Microbes in Food Production (MCQ 6–10) Microbes in Industrial Production (MCQ 11–20) Microbes in Sewage Treatment (MCQ 21–32) Microbes in Biogas Production (MCQ 33–40) Microbes as Biocontrol Agents (MCQ 41–50) Microbes as Biofertilizers (MCQ 51–58) Microbes and Human Welfare – Summary (MCQ 59–60) Multiple Choice Questions (MCQ 61–100)
Microbes in Human Welfare MCQ – Mock Test
Question 1: Which of the following is NOT a major group of microbes?
A. Bacteria
B. Fungi
C. Insects
D. Viruses
C. Insects. While insects are small, they are not microscopic and belong to the animal kingdom.
Question 2: Microbes thrive in various environments. Which of the following is an environment where microbes are typically found?
A. Sterile surgical instruments
B. Deep-sea thermal vents
C. The surface of the sun
D. Distilled water
B. Deep-sea thermal vents. Microbes are known to exist in extreme environments, including very hot places like thermal vents.
Question 3: What is a defining characteristic of microbes that distinguishes them from larger organisms?
A. They are all harmful pathogens.
B. They are only visible with a microscope.
C. They cannot reproduce independently.
D. They are all single-celled organisms.
B. They are only visible with a microscope. This is the key characteristic that defines microbes.
Question 4: Why are some microbes referred to as “proteinacious infectious agents”?
A. They are composed primarily of protein.
B. They infect only protein molecules.
C. They are proteins that can cause infections.
D. They are used as a source of protein in the diet.
C. They are proteins that can cause infections. Prions are an example of such infectious agents.
Question 5: What is the purpose of growing microbes in a culture?
A. To identify the type of microbe.
B. To study the characteristics of microbes.
C. To produce large quantities of microbes for industrial use.
D. All of the above.
D. All of the above. Culturing microbes serves various purposes in research and industry.
Question 6: Which microbe plays a crucial role in the formation of curd from milk?
A. Streptococcus thermophilus
B. Lactobacillus acidophilus
C. Saccharomyces cerevisiae
D. Penicillium notatum
B. Lactobacillus acidophilus. This bacteria converts lactose in milk to lactic acid, causing it to curdle.
Question 7: What process is responsible for the soft and fluffy texture of bread?
A. Pasteurization
B. Fermentation
C. Distillation
D. Sterilization
B. Fermentation. Yeast ferments sugars in the dough, producing carbon dioxide that makes the bread rise.
Question 8: Which of the following is a traditional drink made through microbial fermentation?
A. Cola
B. Toddy
C. Orange juice
D. Mineral water
B. Toddy. This beverage is made by fermenting the sap of palm trees.
Question 9: What is the primary role of microbes in cheese production?
A. Adding flavor and color
B. Preserving the cheese
C. Coagulating milk proteins
D. Preventing spoilage
C. Coagulating milk proteins. Microbes aid in the curdling process, which is essential for cheese production.
Question 10: Which of the following is a type of cheese known for its characteristic blue veins, formed due to the growth of a specific fungus?
A. Cheddar
B. Mozzarella
C. Roquefort
D. Swiss
C. Roquefort. This cheese is ripened with Penicillium roqueforti, giving it the blue veins.
Question 11: What is the name of the large vessel used in industries for growing microbes on a commercial scale?
A. Petri dish
B. Test tube
C. Fermentor
D. Incubator
C. Fermentor. These vessels provide a controlled environment for large-scale microbial growth.
Question 12: Which microbe is commonly used in the production of alcoholic beverages like beer and wine?
A. Lactobacillus
B. Acetobacter
C. Saccharomyces cerevisiae
D. Propionibacterium
C. Saccharomyces cerevisiae. This yeast is used for fermentation in the production of various alcoholic beverages.
Question 13: What was the first antibiotic discovered and used widely to treat bacterial infections?
A. Streptomycin
B. Tetracycline
C. Penicillin
D. Erythromycin
C. Penicillin. Its discovery was a major breakthrough in the fight against bacterial diseases.
Question 14: Which scientist is credited with the accidental discovery of penicillin?
A. Louis Pasteur
B. Alexander Fleming
C. Robert Koch
D. Edward Jenner
B. Alexander Fleming. He observed the antibacterial effect of the Penicillium mold.
Question 15: What is the primary function of the enzyme streptokinase in medical applications?
A. Lowering blood cholesterol
B. Preventing blood clotting
C. Boosting the immune system
D. Dissolving blood clots
D. Dissolving blood clots. Streptokinase is used as a “clot buster” to treat heart attack patients.
Question 16: Which microbe produces the enzyme streptokinase?
A. Streptococcus
B. Aspergillus
C. Trichoderma
D. Monascus
A. Streptococcus. This bacterium is the source of the enzyme streptokinase.
Question 17: What is the primary application of cyclosporin A in medicine?
A. Antibiotic for bacterial infections
B. Antifungal medication
C. Immunosuppressant for organ transplants
D. Cholesterol-lowering agent
C. Immunosuppressant for organ transplants. Cyclosporin A helps prevent organ rejection.
Question 18: Which microbe is used in the commercial production of citric acid?
A. Aspergillus niger
B. Acetobacter aceti
C. Clostridium butylicum
D. Lactobacillus
A. Aspergillus niger. This fungus is widely used for industrial citric acid production.
Question 19: Which of the following is a cholesterol-lowering agent produced by a microbe?
A. Citric acid
B. Streptokinase
C. Cyclosporin A
D. Statins
D. Statins. These drugs inhibit cholesterol synthesis.
Question 20: Which microbe produces statins, the cholesterol-lowering agents?
A. Aspergillus niger
B. Acetobacter aceti
C. Clostridium butylicum
D. Monascus purpureus
D. Monascus purpureus. This yeast is the source of statins.
Question 21: What is the primary component of municipal wastewater or sewage?
A. Industrial waste
B. Agricultural runoff
C. Human excreta
D. Rainwater
C. Human excreta. Sewage mainly consists of human waste along with other organic matter.
Question 22: Why is untreated sewage harmful and cannot be directly released into natural water bodies?
A. It contains pathogenic microbes.
B. It can contaminate drinking water sources.
C. It can cause waterborne diseases.
D. All of the above.
D. All of the above. Untreated sewage poses significant health and environmental risks.
Question 23: What is the primary goal of sewage treatment?
A. To remove all microbes from the water
B. To make the water suitable for drinking
C. To reduce the pollution potential of the wastewater
D. To eliminate all organic matter from the water
C. To reduce the pollution potential of the wastewater. Sewage treatment aims to make the water safe for disposal.
Question 24: What is the main process involved in the primary treatment of sewage?
A. Biological degradation of organic matter
B. Chemical disinfection of the water
C. Physical removal of particles through filtration and sedimentation
D. Aeration to promote microbial growth
C. Physical removal of particles through filtration and sedimentation. This is the first step in sewage treatment.
Question 25: What is the purpose of aeration in the secondary treatment of sewage?
A. To remove large debris from the water
B. To kill all microbes in the water
C. To promote the growth of aerobic microbes
D. To reduce the oxygen content of the water
C. To promote the growth of aerobic microbes. These microbes help break down organic matter.
Question 26: What is BOD a measure of?
A. The amount of oxygen present in water.
B. The amount of organic matter in water.
C. The number of microbes in water.
D. The level of pollution in the air.
B. The amount of organic matter in water. BOD indirectly measures the amount of organic matter by measuring the oxygen required for its decomposition.
Question 27: What is the significance of reducing the BOD of sewage before its release?
A. To increase the oxygen content of the water.
B. To reduce the pollution potential of the sewage.
C. To promote the growth of anaerobic microbes.
D. To make the water safe for drinking.
B. To reduce the pollution potential of the sewage. Lower BOD indicates lower organic pollution.
Question 28: What is the solid material that settles down during primary sewage treatment called?
A. Activated sludge
B. Primary sludge
C. Secondary sludge
D. Anaerobic sludge
B. Primary sludge. This is the sediment formed during the primary treatment.
Question 29: What is the role of anaerobic sludge digesters in sewage treatment?
A. To remove large debris from the sewage.
B. To promote the growth of aerobic microbes.
C. To further digest the activated sludge.
D. To disinfect the treated water.
C. To further digest the activated sludge. Anaerobic bacteria break down the remaining organic matter in the sludge.
Question 30: What is the primary gas produced in anaerobic sludge digesters?
A. Oxygen
B. Carbon dioxide
C. Methane
D. Nitrogen
C. Methane. This is the main component of biogas produced in the digesters.
Question 31: What is the purpose of pumping a small part of the activated sludge back into the aeration tank?
A. To serve as inoculum for further microbial growth.
B. To reduce the volume of the sludge.
C. To increase the BOD of the sewage.
D. To disinfect the aeration tank.
A. To serve as inoculum for further microbial growth. This helps maintain a healthy population of microbes in the aeration tank.
Question 32: What happens to the effluent from the secondary treatment plant?
A. It is discharged into natural water bodies.
B. It is used for irrigation purposes.
C. It is further treated to make it drinkable.
D. It is recycled back into the sewage treatment plant.
A. It is discharged into natural water bodies. After secondary treatment, the water is considered safe for release.
Question 33: Which government initiative aims to save major rivers in India from pollution?
A. Swachh Bharat Abhiyan
B. National Lake Conservation Plan
C. Ganga Action Plan and Yamuna Action Plan
D. National River Linking Project
C. Ganga Action Plan and Yamuna Action Plan. These plans focus on building sewage treatment plants to reduce river pollution.
Question 34: What is the main component of biogas?
A. Methane
B. Carbon dioxide
C. Hydrogen sulfide
D. Nitrogen
A. Methane. Biogas is primarily composed of methane, making it a valuable fuel source.
Question 35: Which group of bacteria plays a crucial role in biogas production?
A. Methanogens
B. Lactobacillus
C. Rhizobium
D. Bacillus
A. Methanogens. These bacteria produce methane during the anaerobic digestion of organic matter.
Question 36: Where are methanogens commonly found?
A. In the rumen of cattle
B. In anaerobic sludge during sewage treatment
C. In biogas plants
D. All of the above
D. All of the above. Methanogens thrive in anaerobic environments rich in organic matter.
Question 37: What is “gobar gas”?
A. Biogas produced from cattle dung
B. Natural gas extracted from underground reservoirs
C. A type of gas used in industrial processes
D. A byproduct of petroleum refining
A. Biogas produced from cattle dung. “Gobar” refers to cattle dung, which is a common source of biogas.
Question 38: What is the purpose of the floating cover in a biogas plant?
A. To collect and store the biogas produced.
B. To prevent the entry of air into the digester.
C. To mix the slurry in the digester.
D. To regulate the temperature of the digester.
A. To collect and store the biogas produced. The cover rises as gas is produced.
Question 39: How is the spent slurry from a biogas plant typically utilized?
A. It is discharged into water bodies.
B. It is used as fertilizer.
C. It is burned as fuel.
D. It is further processed to extract chemicals.
B. It is used as fertilizer. The slurry retains nutrients and is valuable for agriculture.
Question 40: Which organizations have played a significant role in developing biogas production technology in India?
A. IARI (Indian Agricultural Research Institute)
B. KVIC (Khadi and Village Industries Commission)
C. Both A and B
D. Neither A nor B
C. Both A and B. These organizations have promoted biogas production in rural areas.
Question 41: What is the practice of using biological methods to control plant diseases and pests called?
A. Bioremediation
B. Biocontrol
C. Bioaugmentation
D. Biomagnification
B. Biocontrol. This method utilizes natural enemies of pests to keep their populations in check.
Question 42: Which of the following is a benefit of using biocontrol agents over chemical pesticides?
A. Reduced environmental pollution
B. Less harmful to human health
C. Preservation of beneficial organisms
D. All of the above
D. All of the above. Biocontrol offers several advantages over conventional chemical methods.
Question 43: Which insect is commonly known as the “ladybird beetle” and is used as a biocontrol agent against aphids?
A. Dragonfly
B. Ladybug
C. Praying mantis
D. Lacewing
B. Ladybug. Ladybugs are natural predators of aphids and help control their populations.
Question 44: Which bacterium is widely used as a biocontrol agent against several insect pests?
A. Rhizobium
B. Bacillus thuringiensis
C. Escherichia coli
D. Lactobacillus
B. Bacillus thuringiensis. This bacterium produces toxins that are lethal to certain insects.
Question 45: What is the mechanism by which Bacillus thuringiensis (Bt) acts as a biocontrol agent?
A. It competes with harmful bacteria for resources.
B. It produces toxins that kill insect larvae.
C. It attracts natural predators of the pests.
D. It enhances the plant’s immune system.
B. It produces toxins that kill insect larvae. The toxins are activated in the insect’s gut, leading to its death.
Question 46: What is an example of a genetically modified crop that incorporates Bacillus thuringiensis (Bt) toxins for pest resistance?
A. Bt-brinjal
B. Bt-cotton
C. Bt-corn
D. All of the above
B. Bt-cotton. This genetically modified cotton variety expresses Bt toxins to deter insect pests.
Question 47: Which fungus is being explored as a potential biocontrol agent for plant diseases?
A. Aspergillus
B. Penicillium
C. Trichoderma
D. Rhizopus
C. Trichoderma. This fungus exhibits antagonistic effects against various plant pathogens.
Question 48: What are baculoviruses primarily used for in biocontrol applications?
A. Controlling bacterial diseases in plants
B. Suppressing fungal growth in crops
C. Managing insect pests
D. Eliminating weeds
C. Managing insect pests. Baculoviruses are highly specific pathogens that infect and kill insects.
Question 49: What is a key advantage of using baculoviruses as biocontrol agents?
A. They are broad-spectrum insecticides.
B. They have minimal impact on non-target organisms.
C. They are inexpensive to produce.
D. They persist in the environment for a long time.
B. They have minimal impact on non-target organisms. Baculoviruses are known for their host specificity.
Question 50: What is Integrated Pest Management (IPM)?
A. A method that relies solely on chemical pesticides.
B. A holistic approach that combines various pest control methods.
C. A technique that focuses only on biological control agents.
D. A strategy that aims to eradicate all pests from an ecosystem.
B. A holistic approach that combines various pest control methods. IPM integrates different strategies for sustainable pest management.
Question 51: What are biofertilizers?
A. Chemical fertilizers that enhance soil fertility.
B. Organisms that enrich the nutrient quality of the soil.
C. Synthetic compounds that promote plant growth.
D. Genetically modified plants that require less fertilizer.
B. Organisms that enrich the nutrient quality of the soil. Biofertilizers are living organisms that improve soil health.
Question 52: Which of the following microbes is NOT commonly used as a biofertilizer?
A. Bacteria
B. Fungi
C. Cyanobacteria
D. Protozoa
D. Protozoa. While protozoa are microbes, they are not typically used as biofertilizers.
Question 53: What is the primary role of Rhizobium bacteria in agriculture?
A. Nitrogen fixation in the soil
B. Phosphate solubilization
C. Disease suppression
D. Production of growth hormones
A. Nitrogen fixation in the soil. Rhizobium forms symbiotic associations with leguminous plants and converts atmospheric nitrogen into usable forms.
Question 54: Which of the following bacteria is a free-living nitrogen fixer in the soil?
A. Rhizobium
B. Azotobacter
C. Lactobacillus
D. Bacillus
B. Azotobacter. This bacterium can fix nitrogen without forming a symbiotic relationship with plants.
Question 55: What is the symbiotic association between fungi and plant roots called?
A. Lichen
B. Mycorrhiza
C. Nodule
D. Hyphae
B. Mycorrhiza. This mutually beneficial relationship helps plants access nutrients more efficiently.
Question 56: What benefits do plants derive from mycorrhizal associations?
A. Increased phosphorus uptake
B. Resistance to root-borne pathogens
C. Tolerance to salinity and drought
D. All of the above
D. All of the above. Mycorrhizae provide multiple benefits to plants.
Question 57: Which group of microbes is particularly important as biofertilizers in paddy fields?
A. Lactobacillus
B. Cyanobacteria
C. Rhizobium
D. Aspergillus
B. Cyanobacteria. These photosynthetic bacteria can fix nitrogen and add organic matter to the soil.
Question 58: What is the primary advantage of using biofertilizers over chemical fertilizers?
A. Reduced environmental impact
B. Increased crop yield
C. Lower cost
D. Faster action
A. Reduced environmental impact. Biofertilizers are a more sustainable alternative to chemical fertilizers.
Question 59: Which of the following is NOT a way in which microbes contribute to human welfare?
A. Production of antibiotics
B. Sewage treatment
C. Biogas production
D. Depletion of the ozone layer
D. Depletion of the ozone layer. Microbes do not contribute to ozone depletion; in fact, some play a role in ozone formation.
Question 60: How do microbes help in the recycling of water in nature?
A. By converting wastewater into potable water
B. By degrading organic matter in sewage
C. By replenishing groundwater sources
D. By increasing rainfall
B. By degrading organic matter in sewage. Microbes play a crucial role in breaking down organic pollutants in wastewater.
Question 61: Which of the following is a characteristic of the dough used for making idli and dosa?
A. It is fermented by bacteria.
B. It has a puffed-up appearance due to carbon dioxide production.
C. It is a traditional South Indian foo
D. D. All of the above.
D. All of the above. The dough used for idli and dosa is fermented by bacteria, which produce carbon dioxide, giving it a puffed-up appearance. This is a staple in South Indian cuisine.
Question 62: Which of the following is a bacterium responsible for the production of large holes in “Swiss cheese”?
A. Lactobacillus acidophilus
B. Propionibacterium sharmanii
C. Streptococcus thermophilus
D. Penicillium roqueforti
B. Propionibacterium sharmanii. This bacterium produces a significant amount of carbon dioxide during the cheese-making process, resulting in the characteristic large holes in Swiss cheese.
Question 63: Which of the following statements is incorrect regarding antibiotics?
A. They are chemical substances produced by certain microbes.
B. They can kill or inhibit the growth of other microbes.
C. They are used to treat fungal infections only.
D. Penicillin was the first discovered antibiotic.
C. They are used to treat fungal infections only. This statement is incorrect. Antibiotics are primarily used to treat bacterial infections, not fungal ones.
Question 64: Which of the following is not a cholesterol-lowering agent?
A. Statins
B. Streptokinase
C. Cyclosporin A
D. Both B and C
D. Both B and C. Streptokinase is used as a clot buster, and Cyclosporin A is an immunosuppressant. Neither of these directly lowers cholesterol levels.
Question 65: Which of the following microbes is used in the production of acetic acid?
A. Acetobacter aceti
B. Aspergillus niger
C. Clostridium butylicum
D. Lactobacillus
A. Acetobacter aceti. This bacterium is used for the industrial production of acetic acid, the main component of vinegar.
Question 66: Which of the following is not a characteristic of sewage?
A. It is a municipal wastewater.
B. It contains large amounts of organic matter.
C. It is safe to be discharged directly into natural water bodies.
D. It contains pathogenic microbes.
C. It is safe to be discharged directly into natural water bodies. This statement is incorrect. Sewage is harmful due to the presence of pathogens and organic pollutants, and it requires treatment before disposal.
Question 67: Which of the following is not involved in the primary treatment of sewage?
A. Filtration
B. Sedimentation
C. Aeration
D. Removal of floating debris
C. Aeration. Aeration is a key process in secondary treatment, where it promotes the growth of aerobic microbes to break down organic matter.
Question 68: What is the sediment formed during secondary sewage treatment called?
A. Primary sludge
B. Activated sludge
C. Secondary sludge
D. Anaerobic sludge
B. Activated sludge. This sediment is rich in aerobic microbes that have consumed a significant portion of the organic matter in the sewage.
Question 69: What is the process by which certain bacteria convert atmospheric nitrogen into organic forms that plants can use?
A. Denitrification
B. Nitrogen fixation
C. Nitrification
D. Ammonification
B. Nitrogen fixation. This process is crucial for making nitrogen available to plants, which are unable to use nitrogen directly from the atmosphere.
Question 70: Which of the following is a mycorrhizal fungus?
A. Rhizobium
B. Glomus
C. Bacillus
D. Nostoc
B. Glomus. Many members of the genus Glomus form symbiotic associations with plant roots, known as mycorrhizae.
Question 71: Which of the following is not a benefit of mycorrhizal associations for plants?
A. Enhanced photosynthesis
B. Resistance to root-borne pathogens
C. Tolerance to salinity
D. Increased phosphorus uptake
A. Enhanced photosynthesis. While mycorrhizae provide numerous benefits, they do not directly enhance the process of photosynthesis.
Question 72: Which of the following cyanobacteria is not typically used as a biofertilizer in paddy fields?
A. Anabaena
B. Nostoc
C. Oscillatoria
D. Lactobacillus
D. Lactobacillus. This is a lactic acid bacterium commonly found in dairy products and is not involved in nitrogen fixation or used as a biofertilizer in paddy fields.
Question 73: Which of the following is not a characteristic of biogas?
A. It is a mixture of gases produced by microbial activity.
B. It is commonly called “gobar gas” when produced from cattle dung.
C. It cannot be used for cooking or lighting.
D. It is a renewable source of energy.
C. It cannot be used for cooking or lighting. This statement is incorrect. Biogas is commonly used as a fuel source for cooking and lighting, especially in rural areas.
Question 74: Which of the following is not a component of a biogas plant?
A. Aeration tank
B. Digester
C. Floating cover
D. Outlet for biogas supply
A. Aeration tank. Aeration tanks are used in sewage treatment plants to promote aerobic microbial growth, not in biogas plants.
Question 75: Which of the following is not a benefit of using biofertilizers?
A. They increase the nutrient content of the soil.
B. They reduce the dependence on chemical fertilizers.
C. They contribute to environmental pollution.
D. They improve soil health.
C. They contribute to environmental pollution. This statement is incorrect. Biofertilizers are a more environmentally friendly alternative to chemical fertilizers and help reduce pollution.
Question 76: Which of the following is not a traditional food made using microbial fermentation?
A. Curd
B. Dosa
C. Bread
D. None of the above
D. None of the above. All the listed foods—curd, dosa, and bread—are produced using microbial fermentation processes.
Question 77: Which of the following is not an industrial product made using microbes?
A. Biogas
B. Alcohol
C. Penicillin
D. None of the above
D. None of the above. Microbes are used in the industrial production of various products, including biogas, alcohol, and penicillin.
Question 78: Which of the following is not a characteristic of microbes?
A. They are present only in soil and water.
B. They can be grown on nutritive media to form colonies.
C. They are diverse, including bacteria, fungi, and viruses.
D. They can exist in extreme environments like hot springs.
A. They are present only in soil and water. This statement is incorrect. Microbes are ubiquitous and can be found in a wide range of environments, including air, inside our bodies, and even in extreme conditions.
Question 79: Which of the following is not a use of microbes in sewage treatment?
A. Production of oxygen
B. Reduction of BOD
C. Formation of activated sludge
D. Production of biogas
A. Production of oxygen. While some microbes in sewage treatment are aerobic, the primary goal is not oxygen production. The focus is on reducing BOD, forming activated sludge, and generating biogas.
Question 80: Which of the following is not a characteristic of biofertilizers?
A. They are composed of living organisms.
B. They increase the nutrient content of the soil.
C. They have a negative impact on soil fertility.
D. They are a sustainable alternative to chemical fertilizers.
C. They have a negative impact on soil fertility. This statement is incorrect. Biofertilizers enhance soil fertility by providing essential nutrients and improving soil health.
Question 81: Which of the following is a common use of yeast in the food industry?
A. Production of antibiotics
B. Fermentation of dough in bread making
C. Curdling of milk to make cheese
D. Nitrogen fixation in soil
B. Fermentation of dough in bread making. Yeast is a key ingredient in bread making, where it ferments sugars to produce carbon dioxide, causing the dough to rise.
Question 82: Which of the following is a benefit of using microbes in industrial processes?
A. They can produce a wide range of products.
B. They are often more efficient than traditional chemical methods.
C. They can be used in environmentally friendly processes.
D. All of the above
D. All of the above. Microbes offer several advantages in industrial applications, including versatility, efficiency, and sustainability.
Question 83: What is the primary role of microbes in the production of biogas?
A. They break down organic matter in the absence of oxygen.
B. They convert sunlight into chemical energy.
C. They fix nitrogen from the atmosphere.
D. They produce antibiotics.
A. They break down organic matter in the absence of oxygen. This anaerobic digestion process is essential for biogas production.
Question 84: Which of the following is a reason why biocontrol methods are preferred over chemical pesticides?
A. Biocontrol agents are less likely to harm non-target organisms.
B. Biocontrol methods are generally less expensive.
C. Biocontrol agents are less likely to persist in the environment.
D. All of the above
D. All of the above. Biocontrol offers several environmental and economic advantages over chemical pest control.
Question 85: What is the main function of biofertilizers in agriculture?
A. To provide essential nutrients to plants
B. To control plant diseases
C. To kill insect pests
D. To improve soil structure
A. To provide essential nutrients to plants. Biofertilizers enhance soil fertility by supplying nutrients like nitrogen and phosphorus.
Question 86: Which of the following is an example of a microbe used as a biofertilizer?
A. Bacillus thuringiensis
B. Trichoderma
C. Azotobacter
D. Penicillium
C. Azotobacter. This bacterium is a free-living nitrogen fixer that improves soil fertility.
Question 87: What is the term for the use of microbes to clean up pollutants in the environment?
A. Bioremediation
B. Biocontrol
C. Bioaugmentation
D. Biomagnification
A. Bioremediation. This process utilizes microbes to degrade or detoxify pollutants.
Question 88: Which of the following is a potential application of microbes in the future?
A. Production of biofuels
B. Development of new antibiotics
C. Bioremediation of contaminated sites
D. All of the above
D. All of the above. Microbes hold immense potential for various future applications in biotechnology and environmental science.
Question 89: Why is it important to treat sewage before releasing it into natural water bodies?
A. To prevent the spread of waterborne diseases
B. To reduce pollution and protect aquatic life
C. To conserve water resources
D. All of the above
D. All of the above. Sewage treatment is crucial for public health, environmental protection, and water conservation.
Question 90: How do microbes contribute to the cycling of nutrients in ecosystems?
A. They decompose organic matter, releasing nutrients back into the soil.
B. They fix nitrogen from the atmosphere, making it available to plants.
C. They convert organic waste into biogas, a renewable energy source.
D. All of the above
D. All of the above. Microbes play a vital role in nutrient cycling, ensuring the sustainability of ecosystems.
Question 91: Which of the following is NOT a characteristic of Monascus purpureus?
A. It is a yeast.
B. It produces statins.
C. It is used as a biofertilizer.
D. It helps lower blood cholesterol levels.
C. It is used as a biofertilizer. This statement is incorrect. Monascus purpureus is used to produce statins, which are cholesterol-lowering agents, not as a biofertilizer.
Question 92: Which of the following is NOT a benefit of using biofertilizers?
A. They pollute the environment.
B. They enrich the soil with nutrients.
C. They reduce the reliance on chemical fertilizers.
D. They improve soil health.
A. They pollute the environment. This statement is incorrect. Biofertilizers are environmentally friendly and help reduce pollution caused by chemical fertilizers.
Question 93: Which of the following is NOT a characteristic of cyanobacteria?
A. They are autotrophic.
B. They are widely distributed in aquatic and terrestrial environments.
C. They cannot fix atmospheric nitrogen.
D. They add organic matter to the soil.
C. They cannot fix atmospheric nitrogen. This statement is incorrect. Many cyanobacteria, such as Anabaena, Nostoc, and Oscillatoria, are known for their ability to fix atmospheric nitrogen.
Question 94: Which of the following is NOT a way in which microbes contribute to human welfare?
A. They cause a large number of diseases in human beings.
B. They help in the production of various food products.
C. They are used in industrial processes to produce valuable substances.
D. They play a crucial role in sewage treatment.
A. They cause a large number of diseases in human beings. While some microbes are pathogenic, many others are beneficial and contribute to human welfare in various ways.
Question 95: Which of the following is NOT a reason why the use of chemical fertilizers is a cause for concern?
A. They contribute to environmental pollution.
B. They can harm human health if residues are present in food.
C. They improve soil fertility and promote sustainable agriculture.
D. They can disrupt the natural balance of ecosystems.
C. They improve soil fertility and promote sustainable agriculture. This statement is incorrect. While chemical fertilizers can increase crop yield in the short term, their overuse has negative consequences for the environment and long-term soil health.
Question 96: Which of the following is NOT a characteristic of baculoviruses?
A. They are excellent candidates for species-specific insecticidal applications.
B. They have no negative impacts on plants, mammals, birds, or fish.
C. They are effective biocontrol agents against several plant pathogens.
D. They are highly specific pathogens that attack insects and other arthropods.
C. They are effective biocontrol agents against several plant pathogens. This statement is incorrect. Baculoviruses are primarily used for insect control, not for controlling plant pathogens.
Question 97: Which of the following is NOT a characteristic of Trichoderma?
A. It is a free-living fungus.
B. It is a common root ecosystem inhabitant.
C. It is used as an immunosuppressive agent in organ-transplant patients.
D. It is an effective biocontrol agent of several plant pathogens.
C. It is used as an immunosuppressive agent in organ-transplant patients. This statement is incorrect. Cyclosporin A, produced by the fungus Trichoderma polysporum, is used as an immunosuppressive agent, not Trichoderma itself.
Question 98: Which of the following is NOT a characteristic of the BOD test?
A. It measures the rate of oxygen uptake by microorganisms in a water sample.
B. It is a direct measure of the organic matter present in the water.
C. It helps determine the pollution potential of wastewater.
D. A lower BOD value indicates a lower level of organic pollution.
B. It is a direct measure of the organic matter present in the water. This statement is incorrect. BOD is an indirect measure of organic matter, as it assesses the oxygen required for microbial decomposition of that organic matter.
Question 99: Which of the following is NOT a characteristic of a biogas plant?
A. It consists of a concrete tank where bio-wastes are collected.
B. It requires a constant supply of oxygen for optimal functioning.
C. It has an outlet connected to a pipe to supply biogas to nearby houses.
D. The spent slurry can be used as fertilizer.
B. It requires a constant supply of oxygen for optimal functioning. This statement is incorrect. Biogas production relies on anaerobic digestion, meaning it occurs in the absence of oxygen.
Question 100: Which of the following is NOT a way in which microbes play a major role in human welfare?
A. They help in the production of various food products.
B. They are used in industrial processes to produce valuable substances.
C. They play a crucial role in sewage treatment.
D. They are responsible for the depletion of the ozone layer.
D. They are responsible for the depletion of the ozone layer. This statement is incorrect. Microbes are not responsible for ozone layer depletion. In fact, some microbes play a role in ozone formation.
