Microbes in Human Welfare
Each subtopic includes About section, revision page link, 10 preview questions, and practice CTAs.
Microbes in Household Products
SubtopicMicrobes in Household Products under Microbes in Human Welfare for Grade 12 CBSE.
Preview questions (no answers)
- 1.
What is the primary reason for adding a 'starter' to milk?
A.To flavor the milk
B.To provide a high initial population of LAB
C.To cool the milk down
D.To remove the lactose
- 2.
Which of the following is a role of LAB in the stomach?
A.Promoting the growth of pathogens
B.Increasing acidity to harmful levels
C.Checking the growth of disease-causing microbes
D.Digesting cellulose
- 3.
The amount of produced during fermentation determines the ______ in many types of cheese.
A.Sweetness
B.Saltiness
C.Size of the holes
D.Vitamin content
- 4.
Which of the following is a milk product prepared with the help of microbes?
A.Clarified butter (Ghee)
B.Cheese
C.Skimmed milk powder
D.Evaporated milk
- 5.
The production of different types of cheese depends on:
A.The microbe used for fermentation
B.The source of milk
C.The ripeness and flavor desired
D.All of the above
- 6.
How do Lactic Acid Bacteria (LAB) prevent the growth of harmful bacteria in the stomach?
A.By producing alkaline solutions
B.By producing acids and other inhibitory substances
C.By consuming all the nutrients in the stomach
D.By raising the body temperature
- 7.
The scientific name of the bacterium that gives Swiss cheese its characteristic large holes is:
A.Lactobacillus bulgaricus
B.Propionibacterium sharmanii
C.Streptococcus thermophilus
D.Leuconostoc mesenteroides
- 8.
The process of 'leavening' in bread making is specifically the result of which gas being trapped in the dough?
A.Oxygen
B.Nitrogen
C.Carbon dioxide
D.Methane
- 9.
What is the primary difference between the production of Swiss cheese and Roquefort cheese?
A.Swiss cheese uses fungi, while Roquefort uses bacteria
B.Swiss cheese is produced by bacteria, while Roquefort is ripened by fungi
C.Swiss cheese is a 'soft' cheese, while Roquefort is a 'hard' cheese
D.Swiss cheese does not require any microbes, while Roquefort does
- 10.
Which of the following microbes is NOT typically used in the household production of fermented food or beverages?
A.Saccharomyces cerevisiae
B.Lactobacillus
C.Bacillus anthracis
D.Propionibacterium sharmanii
Download the worksheet for Microbes in Human Welfare - Microbes in Household Products to practice offline. It includes additional chapter-level practice questions.
Microbes in Industrial Products
SubtopicMicrobes in Industrial Products under Microbes in Human Welfare for Grade 12 CBSE.
Preview questions (no answers)
- 1.
The use of microbes to produce high-value products like antibiotics and enzymes is part of:
A.Small-scale gardening
B.Industrial microbiology
C.Traditional agriculture
D.Domestic waste management
- 2.
Which bacterium produces Acetic acid industrially?
A.Acetobacter aceti
B.Clostridium butylicum
C.Lactobacillus
D.Streptococcus
- 3.
Which of these is a correct pairing of a product and its application?
A.Statins - Clot buster
B.Cyclosporin A - Immunosuppressant
C.Streptokinase - Cholesterol lowering
D.Protease - Antibiotic
- 4.
Bioactive molecules are those molecules that are:
A.Functionally active in living systems
B.Only produced by plants
C.Used only for making beverages
D.Inert in human bodies
- 5.
The antibiotic Penicillin is derived from a:
A.Bacterium
B.Fungus
C.Protozoan
D.Virus
- 6.
Which of the following bacteria is used for the production of Lactic acid on an industrial scale?
A.Lactobacillus
B.Acetobacter
C.Clostridium
D.Streptococcus
- 7.
Competitive inhibition of the enzyme responsible for cholesterol synthesis is the mechanism of action for:
A.Cyclosporin A
B.Statins
C.Streptokinase
D.Lipase
- 8.
In industrial microbiology, the selection of a specific microbe depends on its taxonomic classification and the metabolic conditions required for product synthesis. Analyze the provided flowchart and identify the correct assignment of industrial products X, Y, Z, and W based on the Kingdom and respiratory conditions.
A.X: Acetic acid; Y: Butyric acid; Z: Citric acid; W: Ethanol
B.X: Butyric acid; Y: Acetic acid; Z: Ethanol; W: Citric acid
C.X: Lactic acid; Y: Ethanol; Z: Citric acid; W: Acetic acid
D.X: Citric acid; Y: Butyric acid; Z: Ethanol; W: Acetic acid
- 9.
What is the primary therapeutic benefit of using Statins for patients with high LDL levels?
A.They directly break down LDL in the bloodstream.
B.They inhibit the microbial synthesis of fat in the intestine.
C.They act as competitive inhibitors for the enzyme HMG-CoA reductase.
D.They stimulate the production of insulin to regulate lipid metabolism.
- 10.
Saccharomyces cerevisiae is used for producing which of the following industrially?
A.Ethanol
B.Statins
C.Acetic Acid
D.Lactic Acid
Download the worksheet for Microbes in Human Welfare - Microbes in Industrial Products to practice offline. It includes additional chapter-level practice questions.
Sewage Treatment
SubtopicSewage Treatment under Microbes in Human Welfare for Grade 12 CBSE.
Preview questions (no answers)
- 1.
What is the relationship between the polluting potential of water and its ?
A.Higher the BOD, lower the polluting potential
B.Higher the BOD, higher the polluting potential
C.BOD has no relation to pollution
D.Pollution only increases when BOD is zero
- 2.
The primary sludge is used for:
A.Making yogurt
B.Landfills or composting
C.Drinking water
D.Inoculum for aeration tanks
- 3.
Activated sludge is mainly composed of:
A.Grit and silt
B.Flocs of decomposer microbes
C.Chemical disinfectants
D.Primary effluent
- 4.
Which of these gases is produced when anaerobic bacteria digest the aerobic bacteria and fungi in the sludge?
A.Oxygen
B.Hydrogen sulphide
C.Ozone
D.Helium
- 5.
The secondary treatment of sewage is fundamentally a:
A.Chemical process
B.Mechanical process
C.Biological process
D.Physical process
- 6.
What is the status of a water body if its BOD is extremely low?
A.It is highly polluted with organic waste
B.It has very little organic matter and is relatively clean
C.It contains high levels of anaerobic bacteria
D.It is unsuitable for aquatic life due to lack of oxygen
- 7.
Which process involves the use of sequential filtration and sedimentation?
A.Secondary treatment
B.Primary treatment
C.Tertiary treatment
D.Biological digestion
- 8.
In the context of the CBSE curriculum on microbes in human welfare, why is sewage treatment considered a 'biological' process despite the use of large tanks and pumps?
A.Because the electricity used is generated from biomass.
B.Because the core removal of organic pollutants is performed by the metabolic activity of microorganisms.
C.Because the tanks are made of biodegradable plastic.
D.Because the grit removed is used as fertilizer for crops.
- 9.
If the primary effluent is directly discharged into a river without secondary treatment, what is the immediate effect on the river's ecology?
A.The river becomes clearer due to the nutrients in the effluent.
B.The of the river drops drastically, leading to the death of fish and other aquatic organisms.
C.The temperature of the river water decreases due to the cooling effect of the effluent.
D.Methanogens in the river immediately start producing large amounts of biogas.
- 10.
What is the significance of the ratio between and (Chemical Oxygen Demand) in assessing sewage treatment efficiency?
A.A high ratio indicates that most of the waste is biodegradable.
B.A low ratio indicates that the sewage is purely organic.
C.The ratio is always in any functional STP.
D.The ratio determines the amount of grit to be removed.
Download the worksheet for Microbes in Human Welfare - Sewage Treatment to practice offline. It includes additional chapter-level practice questions.
Microbes in Production of Biogas
SubtopicMicrobes in Production of Biogas under Microbes in Human Welfare for Grade 12 CBSE.
Preview questions (no answers)
- 1.
Which of the following is a major advantage of using biogas for cooking?
A.It leaves no residue
B.It has a high calorific value and is smoke-free
C.It is very heavy to carry
D.It requires constant oxygen supply
- 2.
What is the primary role of the digester tank in a biogas plant?
A.To store the final gas
B.To provide a site for microbial decomposition
C.To filter the water
D.To collect sunlight
- 3.
The technology of biogas production was highly successful in India due to the efforts of:
A.WHO
B.IARI and KVIC
C.UNESCO
D.Ministry of Finance
- 4.
Which of the following is produced during the anaerobic breakdown of cattle dung?
A.Biogas
B.Petroleum
C.Coal
D.Charcoal
- 5.
Biogas is often considered a 'clean' fuel because:
A.It is colorless
B.It leaves no residue and produces no smoke on burning
C.It is made of pure oxygen
D.It can be stored in open containers
- 6.
What is the primary organic component in the feed for methanogens in the biogas plant?
A.Lignin
B.Cellulose
C.Protein
D.Pectin
- 7.
The production of methane by methanogens is an example of:
A.Aerobic fermentation
B.Anaerobic respiration
C.Photoautotrophy
D.Chemoheterotrophy using oxygen
- 8.
Which of the following describes the 'slurry' mixture fed into the inlet of a biogas plant?
A.A 1:1 ratio of cattle dung and water.
B.Pure cattle dung without any additives.
C.A mixture of cattle dung, water, and lime to increase .
D.Cattle dung mixed with urea and pesticides.
- 9.
In the industrial production of biogas, 'scrubbing' of the gas is often done to remove and . What is the resulting enriched gas called?
A.Syngas
B.Bio-methane
C.Producer gas
D.Water gas
- 10.
What is the biological significance of the 'Syntrophic' relationship between -producing acetogens and -consuming methanogens?
A.It allows for the production of oxygen.
B.It prevents the accumulation of , which would otherwise inhibit the oxidation of fatty acids.
C.It allows methanogens to survive in aerobic conditions.
D.It increases the of the digester to 9.0.
Download the worksheet for Microbes in Human Welfare - Microbes in Production of Biogas to practice offline. It includes additional chapter-level practice questions.
Microbes as Biocontrol Agents and Biofertilizers
SubtopicMicrobes as Biocontrol Agents and Biofertilizers under Microbes in Human Welfare for Grade 12 CBSE.
Preview questions (no answers)
- 1.
Based on the following classification of biofertilizers, which of the following sets correctly identifies the microbial examples for X, Y, and Z?
A.X: , Y: , Z:
B.X: , Y: , Z:
C.X: , Y: , Z:
D.X: , Y: , Z:
- 2.
Which cyanobacterium is often used to fix nitrogen in agricultural fields?
A.B.C.D. - 3.
The use of chemical pesticides is discouraged because they:
A.Are too cheap
B.Are biodegradable
C.Kill both useful and harmful life forms
D.Increase biodiversity
- 4.
Besides phosphorus absorption, mycorrhizal fungi increase plant resistance to:
A.Wind damage
B.Root-borne pathogens
C.Leaf spot disease
D.Cold stress
- 5.
Biofertilizers are organisms that enrich the nutrient quality of the soil. The main sources of biofertilizers are:
A.Bacteria, Fungi, and Cyanobacteria
B.Bacteria, Protozoa, and Viruses
C.Fungi, Algae, and Mosses
D.Cyanobacteria, Viruses, and Fungi
- 6.
Which among the following is a genus of viruses used as biocontrol agents?
A.Bacteriophage
B.C.Retrovirus
D.Tobacco Mosaic Virus
- 7.
What is the 'active' form of the Bt toxin responsible for?
A.Blocking the respiratory passage of the insect
B.Binding to the surface of midgut epithelial cells and creating pores
C.Paralyzing the nervous system of the insect
D.Preventing the insect from molting
- 8.
What is the primary role of the 'inclusion bodies' in the context of Baculoviruses?
A.They store energy for the virus.
B.They protect the viral particles from environmental degradation outside the host.
C.They are used to inject DNA into the plant cells.
D.They help the virus to move through the soil.
- 9.
Which of the following biofertilizers does not fix atmospheric nitrogen but helps in nutrient uptake?
A.B.C.D. - 10.
Which of the following is true about the use of as a biocontrol agent?
A.It is a broad-spectrum insecticide.
B.It was the first fungus used as a biocontrol agent.
C.It is used to control butterfly caterpillars by spraying spores on plants.
D.It acts by entering the insect's circulatory system and causing sepsis.
Download the worksheet for Microbes in Human Welfare - Microbes as Biocontrol Agents and Biofertilizers to practice offline. It includes additional chapter-level practice questions.