Assertion (A): Restriction enzymes are used to cut DNA
molecules at specific sites.
Reason (R): Restriction enzymes recognize and cut DNA at
particular nucleotide sequences called recognition sites.
Answer: (A) Both A and R are true, and R is the correct
explanation of A.
Explanation: Restriction enzymes act as molecular scissors,
recognizing specific DNA sequences (restriction sites) and cutting the DNA at
those points.
Assertion (A): Recombinant DNA technology is used to produce
genetically modified organisms.
Reason (R): Recombinant DNA technology involves combining DNA
from different organisms to create new genetic combinations.
Answer: (A) Both A and R are true, and R is the correct
explanation of A.
Explanation: Recombinant DNA technology involves inserting
foreign DNA into a host organism to create GMOs, enabling the production of
organisms with desired traits.
Assertion (A): Polymerase chain reaction (PCR) is used to
amplify small amounts of DNA.
Reason (R): PCR uses a DNA polymerase enzyme to synthesize
multiple copies of a specific DNA segment in vitro.
Answer: (A) Both A and R are true, and R is the correct
explanation of A.
Explanation: PCR is a technique that allows the amplification
of specific DNA segments by repeatedly replicating the target DNA using DNA
polymerase.
Assertion (A): Biotechnology can be used to produce human
insulin.
Reason (R): Recombinant DNA technology allows the insertion of
the human insulin gene into bacteria, which then produces insulin.
Answer: (A) Both A and R are true, and R is the correct
explanation of A.
Explanation: By inserting the human insulin gene into bacteria
like Escherichia coli, the bacteria can produce insulin, which is then
purified and used for medical purposes.
Assertion (A): Golden rice is a genetically modified crop that
provides enhanced vitamin A content.
Reason (R): Golden rice contains genes from daffodils
and bacteria that enable the production of provitamin A (beta-carotene)
in the rice grains.
Answer: (A) Both A and R are true, and R is the correct
explanation of A.
Explanation: The insertion of specific genes in golden rice
enables the production of beta-carotene, which the body converts into vitamin A,
addressing vitamin A deficiency.
Assertion (A): A vector is necessary for the transfer of
foreign genes into host cells.
Reason (R): Vectors, such as plasmids or viruses, carry foreign
DNA into host cells where it integrates into the genome.
Answer: (A) Both A and R are true, and R is the correct
explanation of A.
Explanation: Vectors are used to transport foreign DNA into
host cells, facilitating gene transfer and subsequent expression of the inserted
genes.
Assertion (A): Gene therapy involves the introduction of new
genes to treat genetic disorders.
Reason (R): Gene therapy aims to replace or repair faulty genes
in patients suffering from genetic diseases.
Answer: (A) Both A and R are true, and R is the correct
explanation of A.
Explanation: Gene therapy involves inserting healthy genes into
the cells of individuals with genetic disorders to replace defective genes and
correct the underlying disease.
Assertion (A): DNA fingerprinting is a technique used to
identify individuals based on their DNA.
Reason (R): DNA fingerprinting exploits the variations in DNA
sequences between individuals, especially in non-coding regions.
Answer: (A) Both A and R are true, and R is the correct
explanation of A.
Explanation: DNA fingerprinting compares non-coding regions of
DNA, which vary significantly between individuals, enabling their
identification.
Assertion (A): Agrobacterium tumefaciens is used as a vector in
plant genetic engineering.
Reason (R): Agrobacterium tumefaciens naturally
transfers DNA to plant cells, making it an ideal tool for genetic modification
of plants.
Answer: (A) Both A and R are true, and R is the correct
explanation of A.
Explanation: Agrobacterium tumefaciens has a natural
ability to transfer DNA into plant cells, making it an effective vector for
introducing foreign genes into plants.
Assertion (A): Recombinant DNA technology has been used to
produce genetically modified crops that are resistant to pests.
Reason (R): Genes encoding for insecticidal proteins like Bt
toxin have been inserted into crops, conferring pest resistance.
Answer: (A) Both A and R are true, and R is the correct
explanation of A.
Explanation: The insertion of genes such as the Bt gene,
derived from Bacillus thuringiensis, enables plants to produce proteins
toxic to specific pests, reducing the need for chemical pesticides.
Assertion (A): Biotechnology is used in the production of
antibiotics.
Reason (R): Microorganisms like Penicillium are used
to produce antibiotics, which are then extracted for medical use.
Answer: (A) Both A and R are true, and R is the correct
explanation of A.
Explanation: Penicillium and other microorganisms are
cultured to produce antibiotics like penicillin, which are used to treat
bacterial infections.
Assertion (A): Genetically modified organisms (GMOs) are
controversial because of potential ecological risks.
Reason (R): The introduction of GMOs into the environment may
disrupt ecosystems by transferring modified genes to wild relatives.
Answer: (A) Both A and R are true, and R is the correct
explanation of A.
Explanation: The ecological concerns surrounding GMOs involve
the unintended spread of modified genes to non-GMO species, which could have
unpredictable ecological impacts.
Assertion (A): The production of recombinant proteins in
bacteria is a common use of biotechnology.
Reason (R): Bacteria like E. coli are capable of
producing large quantities of proteins when supplied with the necessary genetic
information.
Answer: (A) Both A and R are true, and R is the correct
explanation of A.
Explanation: E. coli is frequently used in
biotechnology to produce recombinant proteins such as insulin or growth hormones
by inserting the corresponding gene into the bacterial genome.
Assertion (A): Gene cloning involves making identical copies of
a gene.
Reason (R): Gene cloning uses vectors to introduce a specific
gene into host cells, which then replicate the gene.
Answer: (A) Both A and R are true, and R is the correct
explanation of A.
Explanation: Gene cloning allows the production of multiple
copies of a gene of interest by incorporating it into a host cell that
replicates it during cell division.
Assertion (A): Bt cotton is resistant to pests due to the
presence of the Bt toxin gene.
Reason (R): The Bt toxin gene is derived from Bacillus
thuringiensis and produces a protein toxic to specific insect pests.
Answer: (A) Both A and R are true, and R is the correct
explanation of A.
Explanation: Bt cotton produces a toxin that is harmful to
pests like the bollworm, reducing the need for chemical insecticides.
Assertion (A): Transgenic organisms are organisms that have
been genetically modified.
Reason (R): Transgenic organisms contain DNA from a different
species that is inserted into their genome.
Answer: (A) Both A and R are true, and R is the correct
explanation of A.
Explanation: Transgenic organisms have foreign genes inserted
into their DNA, making them genetically modified organisms (GMOs).
Assertion (A): Restriction enzymes are essential for genetic
modification.
Reason (R): Restriction enzymes cut DNA at specific sites,
allowing foreign DNA to be inserted into vectors for gene transfer.
Answer: (A) Both A and R are true, and R is the correct
explanation of A.
Explanation: Restriction enzymes are used to cut both the
foreign DNA and the vector DNA at specific sites, enabling the insertion of the
gene of interest.
Assertion (A): The use of biotechnology in agriculture has led
to the development of crops with improved nutritional content.
Reason (R): Biotechnology allows the insertion of genes that
produce essential nutrients, such as beta-carotene in golden rice.
Answer: (A) Both A and R are true, and R is the correct
explanation of A.
Explanation: Genetic modification can enhance the nutritional
profile of crops, as seen with golden rice, which provides a source of vitamin A
through the production of beta-carotene.
Assertion (A): Biotechnology has applications in waste
management.
Reason (R): Microorganisms are used in bioremediation to
degrade toxic pollutants and clean up contaminated environments.
Answer: (A) Both A and R are true, and R is the correct
explanation of A.
Explanation: Bioremediation uses microorganisms to degrade
pollutants in soil and water, offering an eco-friendly solution to environmental
contamination.
Assertion (A): Recombinant DNA technology involves combining
genes from different organisms.
Reason (R): By combining DNA from different sources,
recombinant DNA technology enables the creation of organisms with desirable
traits.
Answer: (A) Both A and R are true, and R is the correct
explanation of A.
Explanation: Recombinant DNA technology allows the combination
of DNA from different organisms, resulting in genetically modified organisms
with specific, beneficial traits.
Assertion (A): The use of plasmids as vectors in genetic
engineering has revolutionized the field of biotechnology.
Reason (R): Plasmids are small, circular DNA molecules that can
replicate independently in bacteria, making them ideal vectors for gene
transfer.
Answer: (A) Both A and R are true, and R is the correct
explanation of A.
Explanation: Plasmids can be used as vectors to introduce
foreign DNA into bacteria. Their ability to replicate independently makes them
highly effective for cloning genes.
Assertion (A): The use of genetically modified organisms (GMOs)
in agriculture is controversial.
Reason (R): GMOs can potentially lead to a loss of biodiversity
and the development of resistance in pests to genetically engineered traits.
Answer: (A) Both A and R are true, and R is the correct
explanation of A.
Explanation: The ecological risks associated with GMOs, such as
pest resistance and unintended consequences on biodiversity, are central to the
controversy surrounding their use in agriculture.
Assertion (A): Reverse transcriptase is an enzyme used to
synthesize cDNA from mRNA.
Reason (R): Reverse transcriptase catalyzes the synthesis of a
complementary DNA strand from an RNA template.
Answer: (A) Both A and R are true, and R is the correct
explanation of A.
Explanation: Reverse transcriptase synthesizes complementary
DNA (cDNA) from RNA, a critical step in the creation of cDNA libraries.
Assertion (A): Recombinant DNA technology can be used to
produce human vaccines.
Reason (R): Recombinant DNA technology allows the insertion of
genes encoding viral proteins into bacteria, which can then be used to produce
the vaccines.
Answer: (A) Both A and R are true, and R is the correct
explanation of A.
Explanation: Using recombinant DNA technology, genes from
pathogens can be inserted into bacteria to produce viral proteins, which are
then used to create vaccines.
Assertion (A): Biotechnology can be used to improve crop yield.
Reason (R): Genetic modification of crops can enhance their
resistance to diseases, pests, and environmental stress, leading to higher
yields.
Answer: (A) Both A and R are true, and R is the correct
explanation of A.
Explanation: By introducing genes that confer resistance to
biotic and abiotic stresses, biotechnology can help improve crop productivity.
Assertion (A): A genetically modified organism (GMO) can be
used to produce a therapeutic protein.
Reason (R): GMOs can be engineered to express human proteins,
such as insulin or growth hormone, for medical use.
Answer: (A) Both A and R are true, and R is the correct
explanation of A.
Explanation: GMOs, such as bacteria or yeast, can be modified
to produce human proteins for medical treatments, such as insulin for diabetes.
Assertion (A): Electroporation is a technique used to introduce
foreign DNA into plant cells.
Reason (R): Electroporation involves applying an electrical
field to cells to make their membranes permeable, allowing the uptake of DNA.
Answer: (A) Both A and R are true, and R is the correct
explanation of A.
Explanation: Electroporation is a method used to introduce
foreign DNA into cells by applying electrical pulses that temporarily make the
cell membrane permeable.
Assertion (A): Transgenic animals are created using gene
transfer techniques.
Reason (R): Transgenic animals contain one or more genes from
another organism that have been artificially introduced into their genome.
Answer: (A) Both A and R are true, and R is the correct
explanation of A.
Explanation: Transgenic animals are created by inserting
foreign genes into their genome, allowing the expression of new traits or
production of therapeutic proteins.
Assertion (A): Biotechnology can be applied to environmental
protection through bioremediation.
Reason (R): Bioremediation uses microorganisms to degrade
environmental pollutants and toxic substances.
Answer: (A) Both A and R are true, and R is the correct
explanation of A.
Explanation: Bioremediation employs microorganisms to break
down pollutants, offering a natural method of cleaning up contaminated
environments.
Assertion (A): Bioreactors are used in biotechnology to
cultivate microorganisms.
Reason (R): Bioreactors provide optimal conditions for
microbial growth and the production of bioproducts such as enzymes, antibiotics,
and vaccines.
Answer: (A) Both A and R are true, and R is the correct
explanation of A.
Explanation: Bioreactors are controlled environments that
facilitate the large-scale cultivation of microorganisms, allowing the
production of valuable bioproducts.
Assertion (A): Gene cloning can be used to create multiple
copies of a specific gene.
Reason (R): Gene cloning involves inserting a gene into a
vector, which is then introduced into a host cell where the gene is replicated.
Answer: (A) Both A and R are true, and R is the correct
explanation of A.
Explanation: Gene cloning involves inserting a gene of interest
into a vector, which is introduced into a host cell that replicates the gene,
producing many copies.
Assertion (A): The use of transgenic plants can increase food
security.
Reason (R): Transgenic plants can be engineered to tolerate
extreme environmental conditions, improving yield in difficult growing
conditions.
Answer: (A) Both A and R are true, and R is the correct
explanation of A.
Explanation: Transgenic plants can be modified to be resistant
to drought, salinity, and other stress factors, ensuring better crop yields and
food security.
Assertion (A): The use of genetically modified crops is
strictly regulated by governments.
Reason (R): Genetic modifications in crops can have unforeseen
effects on the environment, requiring strict regulatory controls.
Answer: (A) Both A and R are true, and R is the correct
explanation of A.
Explanation: Due to the potential ecological risks, such as
gene flow to wild species, GMOs are subjected to strict regulatory guidelines to
ensure their safety.
Assertion (A): A gene library is a collection of cloned DNA
fragments.
Reason (R): Gene libraries allow scientists to store and access
large quantities of DNA from different organisms for further study and use.
Answer: (A) Both A and R are true, and R is the correct
explanation of A.
Explanation: Gene libraries consist of cloned DNA fragments,
which are stored for future research, allowing access to the genetic material of
various organisms.
Assertion (A): Biotechnological processes are used in the
production of biofuels.
Reason (R): Microorganisms are engineered to metabolize biomass
into biofuels like ethanol and methane.
Answer: (A) Both A and R are true, and R is the correct
explanation of A.
Explanation: Biotechnology is used to modify microorganisms to
convert organic waste or biomass into biofuels, contributing to sustainable
energy production.
Assertion (A): Genetic engineering can be used to enhance
disease resistance in plants.
Reason (R): Genes from disease-resistant plants or
microorganisms can be inserted into crops to increase their resistance to
pathogens.
Answer: (A) Both A and R are true, and R is the correct
explanation of A.
Explanation: Genetic engineering allows the transfer of genes
conferring disease resistance into crops, improving their ability to withstand
infections.
Assertion (A): Agrobacterium tumefaciens is a natural genetic
engineer of plants.
Reason (R): Agrobacterium tumefaciens transfers part
of its DNA into plant cells, which leads to the formation of crown galls.
Answer: (A) Both A and R are true, and R is the correct
explanation of A.
Explanation: Agrobacterium tumefaciens has a natural
ability to transfer genetic material into plant cells, making it a useful tool
for plant genetic engineering.
Assertion (A): Biotechnology has applications in the treatment
of diseases through the production of therapeutic proteins.
Reason (R): Biotechnological methods enable the production of
human proteins such as insulin, growth hormones, and monoclonal antibodies in
microorganisms.
Answer: (A) Both A and R are true, and R is the correct
explanation of A.
Explanation: Biotechnology allows for the mass production of
therapeutic proteins in microorganisms, which can be used to treat various
diseases, such as diabetes and cancer.
Assertion (A): Gene therapy holds promise for treating genetic
disorders.
Reason (R): Gene therapy involves replacing defective genes
with healthy ones, potentially curing inherited diseases.
Answer: (A) Both A and R are true, and R is the correct
explanation of A.
Explanation: Gene therapy offers a method to treat genetic
disorders by replacing or repairing faulty genes, thereby curing or alleviating
the symptoms of inherited diseases.
Assertion (A): Polymerase Chain Reaction (PCR) is used to
amplify DNA sequences.
Reason (R): PCR uses heat-stable enzymes to replicate DNA,
creating millions of copies of the target sequence.
Answer: (A) Both A and R are true, and R is the correct
explanation of A.
Explanation: PCR is a widely used technique to amplify specific
DNA sequences, enabling their analysis and use in various biotechnological
applications.
Assertion (A): A recombinant DNA molecule is formed when two
different DNA fragments are joined together.
Reason (R): DNA ligase is an enzyme that facilitates the
formation of phosphodiester bonds between the DNA fragments.
Answer: (A) Both A and R are true, and R is the correct
explanation of A.
Explanation: Recombinant DNA molecules are formed when two
different DNA fragments are joined by the enzyme DNA ligase, which creates a
stable covalent bond between them.
Assertion (A): The polymerase chain reaction (PCR) process can
amplify even minute amounts of DNA.
Reason (R): PCR involves repeated cycles of DNA denaturation,
primer annealing, and DNA synthesis, allowing exponential amplification of a
target DNA sequence.
Answer: (A) Both A and R are true, and R is the correct
explanation of A.
Explanation: PCR amplifies small DNA samples exponentially,
making it a powerful tool for detecting or cloning DNA even from trace amounts.
Assertion (A): Genetically modified crops are designed to
resist specific pests.
Reason (R): Genetic modification can introduce genes that
produce toxins, making plants toxic to specific pests but safe for humans and
animals.
Answer: (A) Both A and R are true, and R is the correct
explanation of A.
Explanation: Genetic modification can introduce genes that
produce insecticidal proteins, such as Bt toxin, to make crops resistant to
pests.
Assertion (A): The enzyme restriction endonuclease is used to
cut DNA at specific sequences.
Reason (R): Restriction endonucleases recognize palindromic DNA
sequences and cut both strands of DNA at the recognition site.
Answer: (A) Both A and R are true, and R is the correct
explanation of A.
Explanation: Restriction endonucleases recognize specific DNA
sequences, usually palindromes, and cut the DNA at these sites, which is
essential in cloning and recombinant DNA technology.
Assertion (A): Genetic modification of microorganisms has
helped in the production of insulin.
Reason (R): The gene for human insulin can be inserted into a
bacterium, which then expresses the insulin protein for medical use.
Answer: (A) Both A and R are true, and R is the correct
explanation of A.
Explanation: The gene for insulin is inserted into bacteria,
which then produce insulin, enabling mass production for medical purposes.
Assertion (A): A bioreactor is used in the production of
insulin through biotechnology.
Reason (R): A bioreactor is a controlled environment in which
microorganisms can grow and produce proteins such as insulin.
Answer: (A) Both A and R are true, and R is the correct
explanation of A.
Explanation: Bioreactors provide the optimal conditions for
microbial growth, leading to the mass production of proteins like insulin
through fermentation.
Assertion (A): Cry proteins from Bacillus thuringiensis
are used to make crops pest-resistant.
Reason (R): Cry proteins act as insecticides that are toxic to
certain insects, thereby protecting crops from pests.
Answer: (A) Both A and R are true, and R is the correct
explanation of A.
Explanation: Bacillus thuringiensis produces Cry
proteins, which are toxic to specific pests and are used in genetic engineering
to make crops resistant to those pests.
Assertion (A): The use of genetic modification can help improve
the nutritional content of crops.
Reason (R): Genetic modification can enhance the levels of
vitamins, minerals, and other nutrients in crops to combat nutritional
deficiencies.
Answer: (A) Both A and R are true, and R is the correct
explanation of A.
Explanation: Genetic modification can be used to increase the
nutritional value of crops, such as through the production of Golden Rice, which
contains enhanced levels of vitamin A.
Assertion (A): Biotechnology is used in medicine to produce
therapeutic proteins.
Reason (R): Recombinant DNA technology allows microorganisms to
produce human proteins, such as insulin, growth hormones, and monoclonal
antibodies, for medical treatments.
Answer: (A) Both A and R are true, and R is the correct
explanation of A.
Explanation: Biotechnology enables microorganisms to produce
therapeutic proteins by introducing human genes into them, which are used to
treat diseases such as diabetes and cancer.
Assertion (A): The production of Bt cotton involves the
insertion of a gene from Bacillus thuringiensis.
Reason (R): The inserted gene in Bt cotton produces an
insecticidal protein that makes the cotton plant resistant to specific pests.
Answer: (A) Both A and R are true, and R is the correct
explanation of A.
Explanation: Bt cotton is genetically modified to express a
gene from Bacillus thuringiensis that produces a toxin harmful to
certain insect pests, reducing the need for chemical pesticides.