Assertion (A): Microorganisms play a crucial role in the
preparation of food.
Reason (R): Fermentation by microorganisms is essential for
producing a variety of food products like curd, bread, and alcohol.
Answer: (A) Both A and R are true, and R is the correct
explanation of A.
Explanation: Microorganisms, through fermentation, are involved
in food preservation and preparation, enhancing taste and nutritional value, as
seen in products like curd, bread, and alcoholic beverages.
Assertion (A): Biogas is produced by the anaerobic degradation
of organic matter.
Reason (R): Microorganisms such as bacteria break down organic
material in the absence of oxygen to produce methane gas, a major component of
biogas.
Answer: (A) Both A and R are true, and R is the correct
explanation of A.
Explanation: Anaerobic bacteria decompose organic waste to
produce methane, carbon dioxide, and other gases, which make up biogas, used as
an alternative fuel.
Assertion (A): Microorganisms are used in sewage treatment.
Reason (R): Microorganisms break down organic matter in sewage,
thereby purifying water.
Answer: (A) Both A and R are true, and R is the correct
explanation of A.
Explanation: Microorganisms, through biochemical processes,
decompose organic waste in sewage, significantly improving water quality and
reducing pollution.
Assertion (A): Antibiotics are substances produced by
microorganisms.
Reason (R): Antibiotics are chemical substances that kill or
inhibit the growth of bacteria without harming the host.
Answer: (A) Both A and R are true, and R is the correct
explanation of A.
Explanation: Antibiotics like penicillin are naturally produced
by fungi and bacteria, and they inhibit the growth of specific bacteria, helping
in disease treatment.
Assertion (A): Vaccines are prepared from weakened or killed
microorganisms.
Reason (R): Vaccines stimulate the immune system to produce
antibodies, providing immunity against future infections.
Answer: (A) Both A and R are true, and R is the correct
explanation of A.
Explanation: Vaccines are made from attenuated or killed
microorganisms that stimulate the immune system to recognize and fight off the
pathogens.
Assertion (A): Fungi are used in the production of antibiotics.
Reason (R): Fungi such as Penicillium produce
penicillin, an antibiotic that kills bacteria.
Answer: (A) Both A and R are true, and R is the correct
explanation of A.
Explanation: The fungus Penicillium produces
penicillin, which is one of the first antibiotics used to treat bacterial
infections.
Assertion (A): Microorganisms are used in the production of
alcoholic beverages.
Reason (R): Yeasts ferment sugars in grains and fruits to
produce ethanol, which is the key component of alcohol.
Answer: (A) Both A and R are true, and R is the correct
explanation of A.
Explanation: Yeast fermentation is essential for producing
alcoholic beverages, as yeasts convert sugars into ethanol and carbon dioxide.
Assertion (A): Microbes are used in the production of vitamins.
Reason (R): Certain bacteria and fungi are capable of
synthesizing vitamins like B12, which are important for human nutrition.
Answer: (A) Both A and R are true, and R is the correct
explanation of A.
Explanation: Bacteria like Propionibacterium and
Lactobacillus can produce essential vitamins such as vitamin B12, which is
important for human health.
Assertion (A): Nitrogen fixation in plants is carried out by
bacteria.
Reason (R): Bacteria like Rhizobium convert
atmospheric nitrogen into usable forms like ammonia for plants.
Answer: (A) Both A and R are true, and R is the correct
explanation of A.
Explanation: Rhizobium and other nitrogen-fixing
bacteria convert atmospheric nitrogen into ammonia, which is used by plants for
growth.
Assertion (A): Microorganisms are involved in the process of
nitrogen cycle.
Reason (R): Bacteria fix atmospheric nitrogen and convert it
into nitrates and nitrites, which are absorbed by plants.
Answer: (A) Both A and R are true, and R is the correct
explanation of A.
Explanation: Nitrogen-fixing bacteria and nitrifying bacteria
play a critical role in the nitrogen cycle by converting atmospheric nitrogen
into usable forms for plants.
Assertion (A): The process of fermentation is used in the
production of biogas.
Reason (R): Microorganisms break down organic matter
anaerobically to release methane, a key component of biogas.
Answer: (A) Both A and R are true, and R is the correct
explanation of A.
Explanation: Fermentation by anaerobic microorganisms produces
methane, which is collected as biogas, an important renewable energy source.
Assertion (A): Lactic acid bacteria are used in dairy
fermentation.
Reason (R): These bacteria convert lactose into lactic acid,
which curdles the milk and produces yogurt and other dairy products.
Answer: (A) Both A and R are true, and R is the correct
explanation of A.
Explanation: Lactic acid bacteria, such as Lactobacillus,
ferment lactose into lactic acid, a process that curdles milk and leads to the
production of yogurt.
Assertion (A): Microorganisms play a role in biodegradation.
Reason (R): Microorganisms break down organic pollutants,
reducing environmental contamination.
Answer: (A) Both A and R are true, and R is the correct
explanation of A.
Explanation: Microorganisms decompose organic matter, including
pollutants like oils and plastics, in a process called biodegradation, which
helps clean the environment.
Assertion (A): Microorganisms can be used in the production of
enzymes.
Reason (R): Certain bacteria and fungi produce enzymes that are
commercially important in industries like food processing and detergents.
Answer: (A) Both A and R are true, and R is the correct
explanation of A.
Explanation: Microorganisms produce enzymes like amylase,
protease, and cellulase, which are widely used in various industries.
Assertion (A): Bacteria play a crucial role in the
decomposition of organic matter.
Reason (R): Bacteria break down complex organic compounds into
simpler substances, enriching the soil.
Answer: (A) Both A and R are true, and R is the correct
explanation of A.
Explanation: Bacteria, as decomposers, break down dead organic
matter into simpler compounds like carbon dioxide and nutrients, contributing to
soil fertility.
Assertion (A): Microorganisms are used in the production of
biofuels.
Reason (R): Microorganisms like bacteria and algae produce
ethanol and methane, which are used as biofuels.
Answer: (A) Both A and R are true, and R is the correct
explanation of A.
Explanation: Algae and bacteria are used to produce biofuels
like ethanol and methane through fermentation processes, providing an
alternative to fossil fuels.
Assertion (A): Genetic engineering of microorganisms is used to
produce insulin.
Reason (R): By inserting the human insulin gene into bacteria,
they can be made to produce insulin, which is used to treat diabetes.
Answer: (A) Both A and R are true, and R is the correct
explanation of A.
Explanation: Recombinant DNA technology allows bacteria to
produce human insulin, providing an effective treatment for diabetes.
Assertion (A): Antibiotic resistance is a growing concern in
medicine.
Reason (R): Overuse and misuse of antibiotics lead to the
development of antibiotic-resistant strains of bacteria.
Answer: (A) Both A and R are true, and R is the correct
explanation of A.
Explanation: The overuse and inappropriate use of antibiotics
have led to the emergence of antibiotic-resistant bacteria, posing a significant
public health risk.
Assertion (A): Biotechnology uses microorganisms to produce
important chemicals.
Reason (R): Microorganisms can be engineered to produce
biochemicals such as vitamins, amino acids, and enzymes.
Answer: (A) Both A and R are true, and R is the correct
explanation of A.
Explanation: Biotechnology harnesses the metabolic capabilities
of microorganisms to produce essential chemicals like amino acids, enzymes, and
vitamins for industrial use.
Assertion (A): Bioremediation uses microorganisms to clean
polluted environments.
Reason (R): Microorganisms degrade or transform pollutants,
such as oil spills, into non-toxic substances.
Answer: (A) Both A and R are true, and R is the correct
explanation of A.
Explanation: Bioremediation involves using microorganisms to
degrade pollutants, such as hydrocarbons from oil spills, making the environment
cleaner and safer.
Assertion (A): Microbes can be used to detoxify industrial
effluents.
Reason (R): Certain microbes can break down toxic substances in
industrial waste, reducing environmental hazards.
Answer: (A) Both A and R are true, and R is the correct
explanation of A.
Explanation: Microorganisms are used to degrade toxic
substances in industrial effluents, aiding in pollution control and
environmental conservation.
Assertion (A): Yeast is used in the fermentation process.
Reason (R): Yeast ferments sugars into alcohol and carbon
dioxide, which is used in the production of bread and alcoholic beverages.
Answer: (A) Both A and R are true, and R is the correct
explanation of A.
Explanation: Yeast converts sugars into alcohol and carbon
dioxide through fermentation, which is essential in bread-making and brewing.
Assertion (A): Microbes are used in the production of fermented
foods.
Reason (R): Microorganisms like bacteria and fungi are involved
in the fermentation of foods such as pickles, cheese, and sauerkraut.
Answer: (A) Both A and R are true, and R is the correct
explanation of A.
Explanation: Microorganisms like Lactobacillus and
Penicillium are used to ferment foods, enhancing their taste, texture, and
nutritional value.
Assertion (A): Probiotics are live microorganisms that provide
health benefits.
Reason (R): Probiotics help in maintaining gut health by
balancing the gut microbiota and improving digestion.
Answer: (A) Both A and R are true, and R is the correct
explanation of A.
Explanation: Probiotics are beneficial microorganisms that,
when consumed, help in maintaining a healthy balance of gut bacteria, improving
digestion and immune function.
Assertion (A): Bacteria can be used in the production of
enzymes for industrial applications.
Reason (R): Microbial enzymes are used in industries such as
detergents, textiles, and food processing due to their efficiency and
specificity.
Answer: (A) Both A and R are true, and R is the correct
explanation of A.
Explanation: Bacteria like Bacillus species produce
enzymes like protease and amylase, which are widely used in industrial
processes.
Assertion (A): Nitrogen fixation is an important process for
plant growth.
Reason (R): Certain bacteria convert nitrogen into a form that
plants can absorb, ensuring their nutrient needs are met.
Answer: (A) Both A and R are true, and R is the correct
explanation of A.
Explanation: Nitrogen-fixing bacteria like Rhizobium
convert atmospheric nitrogen into ammonia, which plants can utilize for growth.
Assertion (A): Antibiotics like penicillin are derived from
fungi.
Reason (R): Penicillin, discovered by Alexander Fleming, is
produced by the fungus Penicillium and is used to treat bacterial
infections.
Answer: (A) Both A and R are true, and R is the correct
explanation of A.
Explanation: Penicillin is a fungal-derived antibiotic that has
been crucial in treating bacterial infections since its discovery by Alexander
Fleming.
Assertion (A): Microbes can help in the fermentation of food
and beverages.
Reason (R): Microbial enzymes break down complex carbohydrates
into simpler sugars, producing alcohol and other byproducts.
Answer: (A) Both A and R are true, and R is the correct
explanation of A.
Explanation: Microbial enzymes facilitate the breakdown of
sugars, leading to the production of alcohol, carbon dioxide, and other
fermented food products.
Assertion (A): Microbes play a role in agricultural
sustainability.
Reason (R): Microorganisms contribute to soil fertility through
nitrogen fixation, decomposition, and nutrient cycling.
Answer: (A) Both A and R are true, and R is the correct
explanation of A.
Explanation: Microorganisms improve soil health by contributing
to nutrient cycles, breaking down organic matter, and fixing nitrogen, all of
which are essential for sustainable agriculture.
Assertion (A): Genetic engineering has led to the production of
genetically modified crops.
Reason (R): Genetic modification involves inserting genes from
microorganisms to impart beneficial traits such as pest resistance and drought
tolerance.
Answer: (A) Both A and R are true, and R is the correct
explanation of A.
Explanation: Genetic engineering in crops involves using genes
from microorganisms to create crops with desirable traits, enhancing crop yield
and resistance to pests.
Assertion (A): Microorganisms are used in the production of
fermented foods.
Reason (R): Yeast and bacteria help in the fermentation of
foods like bread, pickles, and yogurt, giving them unique flavors and textures.
Answer: (A) Both A and R are true, and R is the correct
explanation of A.
Explanation: Yeast and bacteria are crucial in the fermentation
process, which enhances the flavor, texture, and nutritional value of many
foods.
Assertion (A): Microbes can be used to clean up oil spills.
Reason (R): Certain microorganisms can break down hydrocarbons
in oil into simpler, non-toxic substances.
Answer: (A) Both A and R are true, and R is the correct
explanation of A.
Explanation: Bioremediation uses microorganisms to degrade
pollutants like oil, reducing environmental harm and promoting the recovery of
ecosystems.
Assertion (A): Bacteria are used in the production of
antibiotics.
Reason (R): Antibiotics like penicillin are derived from
bacteria and fungi and are used to treat bacterial infections.
Answer: (A) Both A and R are true, and R is the correct
explanation of A.
Explanation: Penicillin, discovered from the fungus
Penicillium, is an antibiotic that kills or inhibits bacterial growth,
revolutionizing the treatment of infections.
Assertion (A): Microorganisms are used in sewage treatment.
Reason (R): Certain bacteria help in breaking down organic
matter in sewage, converting it into simpler, less harmful compounds.
Answer: (A) Both A and R are true, and R is the correct
explanation of A.
Explanation: In sewage treatment plants, bacteria decompose
organic matter, purifying the water before it is released into the environment.
Assertion (A): Microbial enzymes are used in food processing.
Reason (R): Enzymes like amylases and proteases help in
breaking down starches and proteins in food, improving texture and flavor.
Answer: (A) Both A and R are true, and R is the correct
explanation of A.
Explanation: Microbial enzymes aid in the breakdown of complex
molecules, making the food processing process faster and more efficient.
Assertion (A): Microorganisms are involved in nitrogen
fixation.
Reason (R): Certain bacteria, such as Rhizobium,
convert atmospheric nitrogen into ammonia, which is usable by plants for growth.
Answer: (A) Both A and R are true, and R is the correct
explanation of A.
Explanation: Nitrogen-fixing bacteria, like Rhizobium,
play a crucial role in converting nitrogen into forms that plants can utilize,
essential for plant health.
Assertion (A): Yeast is used in baking bread.
Reason (R): Yeast ferments sugars in dough, producing carbon
dioxide, which causes the dough to rise and gives bread its texture.
Answer: (A) Both A and R are true, and R is the correct
explanation of A.
Explanation: Yeast is essential in bread-making because it
ferments sugars and produces gases that make the dough rise, giving bread its
soft texture.
Assertion (A): Microbes are used in the production of alcoholic
beverages.
Reason (R): Yeast ferments sugars into ethanol, which is the
alcohol found in beverages like wine, beer, and spirits.
Answer: (A) Both A and R are true, and R is the correct
explanation of A.
Explanation: Yeast fermentation is responsible for the
production of ethanol (alcohol), a key ingredient in various alcoholic
beverages.
Assertion (A): Microbial bioreactors are used for the
production of antibiotics.
Reason (R): Certain bacteria and fungi are cultured in
bioreactors to produce antibiotics in large quantities for medical use.
Answer: (A) Both A and R are true, and R is the correct
explanation of A.
Explanation: Microbial bioreactors provide the ideal conditions
for microorganisms to produce antibiotics, which are then harvested for medical
applications.
Assertion (A): Bioremediation is an eco-friendly way to treat
environmental pollution.
Reason (R): Microorganisms degrade harmful pollutants, like oil
or toxic chemicals, turning them into harmless substances.
Answer: (A) Both A and R are true, and R is the correct
explanation of A.
Explanation: Bioremediation uses microorganisms to clean up
polluted environments, making it a sustainable, environmentally friendly
solution.
Assertion (A): Microbes play a role in the decomposition of
organic matter.
Reason (R): Decomposers, like bacteria and fungi, break down
dead organic material, recycling nutrients back into the ecosystem.
Answer: (A) Both A and R are true, and R is the correct
explanation of A.
Explanation: Decomposing microbes break down dead plant and
animal matter, returning vital nutrients like nitrogen and phosphorus back to
the soil.
Assertion (A): Probiotics are beneficial microorganisms.
Reason (R): Probiotics help in maintaining the balance of
beneficial bacteria in the digestive system, improving gut health.
Answer: (A) Both A and R are true, and R is the correct
explanation of A.
Explanation: Probiotics support digestive health by promoting a
healthy gut microbiota, which aids digestion and boosts immunity.
Assertion (A): Microorganisms are used in the production of
biogas.
Reason (R): Anaerobic bacteria break down organic waste in the
absence of oxygen, producing methane, which can be used as a fuel.
Answer: (A) Both A and R are true, and R is the correct
explanation of A.
Explanation: Microbial activity in anaerobic conditions helps
produce methane, a key component of biogas, which is used as a renewable energy
source.
Assertion (A): Antibiotic resistance in bacteria is a growing
problem.
Reason (R): The overuse and misuse of antibiotics contribute to
the development of antibiotic-resistant bacteria.
Answer: (A) Both A and R are true, and R is the correct
explanation of A.
Explanation: The excessive use of antibiotics allows bacteria
to evolve resistance, making infections harder to treat.
Assertion (A): Microbial biofilms can form on surfaces.
Reason (R): Microorganisms secrete sticky substances that allow
them to adhere to surfaces, forming protective biofilms.
Answer: (A) Both A and R are true, and R is the correct
explanation of A.
Explanation: Microbes can form biofilms on various surfaces,
including medical devices and pipes, making infections harder to treat.
Assertion (A): Genetic engineering has led to the development
of genetically modified organisms (GMOs).
Reason (R): Genetic engineering involves altering an organism’s
genetic material, often using bacterial genes, to introduce desired traits.
Answer: (A) Both A and R are true, and R is the correct
explanation of A.
Explanation: Genetic engineering techniques have enabled the
modification of organisms, including plants, to have traits such as pest
resistance or enhanced nutritional value.
Assertion (A): Microbes can be used in the production of
vitamins.
Reason (R): Certain bacteria and fungi can synthesize vitamins
like vitamin B12, which are essential for human health.
Answer: (A) Both A and R are true, and R is the correct
explanation of A.
Explanation: Some microorganisms are capable of producing
vitamins, which are then used as dietary supplements or in food fortification.
Assertion (A): Microbes can be genetically modified to produce
useful products.
Reason (R): Genetic modification of microorganisms can enable
them to produce pharmaceuticals, enzymes, and biofuels.
Answer: (A) Both A and R are true, and R is the correct
explanation of A.
Explanation: Genetic modification of microorganisms has
revolutionized industries, enabling the production of valuable products like
insulin, enzymes, and biofuels.
Assertion (A): Microbes help in the production of vinegar.
Reason (R): Acetic acid bacteria convert ethanol into acetic
acid, producing vinegar in the process.
Answer: (A) Both A and R are true, and R is the correct
explanation of A.
Explanation: Acetic acid bacteria are responsible for
fermenting ethanol into acetic acid, the main component of vinegar.
Assertion (A): Microorganisms can be used in pest control.
Reason (R): Certain microbes, such as Bacillus
thuringiensis, produce toxins that are harmful to insects but safe for
humans and animals.
Answer: (A) Both A and R are true, and R is the correct
explanation of A.
Explanation: Microbial biopesticides like Bacillus
thuringiensis are used as a natural and eco-friendly way to control pest
populations.