ROUTERA


Chapter 12 Biotechnology and its Applications

Class 12th Biology Chapter Assertion and Reason


1.

Assertion (A): Biotechnology is the manipulation of living organisms or their components to produce useful products.
Reason (R): Biotechnology includes the use of organisms to synthesize substances like enzymes, antibiotics, and hormones.
Answer: (A) Both A and R are true, and R is the correct explanation of A.
Explanation: Biotechnology involves manipulating organisms to produce substances like enzymes and hormones that are valuable in industries such as pharmaceuticals and agriculture.


2.

Assertion (A): Genetic engineering is a branch of biotechnology that involves modifying the DNA of an organism.
Reason (R): Genetic engineering techniques enable scientists to introduce foreign genes into organisms, altering their traits.
Answer: (A) Both A and R are true, and R is the correct explanation of A.
Explanation: Genetic engineering uses recombinant DNA technology to modify an organism’s genome by adding, removing, or altering genes, resulting in genetically modified organisms (GMOs).


3.

Assertion (A): Biotechnology has helped in the development of genetically modified crops.
Reason (R): GM crops are engineered to resist pests, tolerate herbicides, and enhance nutrient content.
Answer: (A) Both A and R are true, and R is the correct explanation of A.
Explanation: Genetic modifications in crops, such as Bt cotton or golden rice, enhance crop productivity, improve resistance to pests, and increase nutrient content.


4.

Assertion (A): Transgenic organisms are organisms that have been genetically modified by incorporating foreign DNA.
Reason (R): Transgenic organisms are produced by inserting a gene of interest into the genome of the organism using techniques like gene cloning.
Answer: (A) Both A and R are true, and R is the correct explanation of A.
Explanation: Transgenic organisms are engineered to carry foreign genes, which confer new traits, such as disease resistance or improved growth, making them useful in agriculture and medicine.


5.

Assertion (A): Gene therapy is used to treat genetic disorders by correcting defective genes.
Reason (R): Gene therapy involves introducing functional genes into a patient’s cells to replace defective or missing ones.
Answer: (A) Both A and R are true, and R is the correct explanation of A.
Explanation: Gene therapy aims to treat genetic disorders by adding, deleting, or altering genes inside a patient's cells to correct genetic defects.


6.

Assertion (A): Recombinant DNA technology is used in the production of insulin.
Reason (R): Insulin is produced by inserting the human insulin gene into bacterial DNA, which allows bacteria to produce insulin.
Answer: (A) Both A and R are true, and R is the correct explanation of A.
Explanation: Recombinant DNA technology enables the insertion of the human insulin gene into bacteria, which then produce insulin that is purified and used for treating diabetes.


7.

Assertion (A): Biofortification is a method used to improve the nutritional value of crops.
Reason (R): Biofortified crops contain higher levels of essential nutrients, such as vitamins and minerals, compared to conventional crops.
Answer: (A) Both A and R are true, and R is the correct explanation of A.
Explanation: Biofortification involves the genetic modification of crops to enhance their nutritional content, addressing deficiencies in essential micronutrients.


8.

Assertion (A): Biodegradable plastics are derived from renewable biological resources.
Reason (R): Biodegradable plastics are made from natural polymers, such as starch or polylactic acid, which break down under environmental conditions.
Answer: (A) Both A and R are true, and R is the correct explanation of A.
Explanation: Biodegradable plastics, produced from renewable resources like starch or sugar, decompose naturally in the environment, reducing pollution.


9.

Assertion (A): Bioremediation uses microorganisms to clean up pollutants in the environment.
Reason (R): Certain microorganisms are capable of metabolizing harmful substances, transforming them into harmless by-products.
Answer: (A) Both A and R are true, and R is the correct explanation of A.
Explanation: Bioremediation is a process where microorganisms degrade environmental pollutants such as oil spills, heavy metals, or organic waste, converting them into less toxic substances.


10.

Assertion (A): Fermentation is used in the production of various food products and beverages.
Reason (R): Fermentation involves the conversion of organic substrates into useful products, such as alcohol and lactic acid, by microorganisms.
Answer: (A) Both A and R are true, and R is the correct explanation of A.
Explanation: Microbial fermentation is used to produce products like ethanol, cheese, yogurt, and bread, where microorganisms like yeast or bacteria break down sugars to produce alcohol or acids.


11.

Assertion (A): Genetically modified (GM) organisms have been developed for the production of therapeutic proteins.
Reason (R): GM organisms, such as bacteria or plants, can be engineered to produce therapeutic proteins like antibodies, hormones, and vaccines.
Answer: (A) Both A and R are true, and R is the correct explanation of A.
Explanation: Genetic modifications allow microorganisms and plants to produce valuable proteins used in medicine, including insulin, vaccines, and monoclonal antibodies.


12.

Assertion (A): PCR (Polymerase Chain Reaction) is a technique used to amplify small segments of DNA.
Reason (R): PCR uses repeated cycles of DNA denaturation, primer binding, and DNA synthesis to make millions of copies of a specific DNA segment.
Answer: (A) Both A and R are true, and R is the correct explanation of A.
Explanation: PCR is a method to amplify a small DNA segment by repeating cycles of denaturation, primer annealing, and DNA synthesis, leading to the exponential amplification of the target sequence.


13.

Assertion (A): Antibodies are used in immunotherapy to treat cancer.
Reason (R): Monoclonal antibodies are designed to target specific cancer cells, delivering therapeutic agents directly to the tumor site.
Answer: (A) Both A and R are true, and R is the correct explanation of A.
Explanation: Monoclonal antibodies are used in targeted cancer therapies, where they bind to specific cancer cell antigens, delivering drugs or radiation directly to the tumor site.


14.

Assertion (A): Bt cotton is genetically engineered to resist insect pests.
Reason (R): Bt cotton contains a gene from Bacillus thuringiensis that produces a protein toxic to certain insects, protecting the cotton crop.
Answer: (A) Both A and R are true, and R is the correct explanation of A.
Explanation: Bt cotton has been modified to express Bacillus thuringiensis toxin, which is harmful to insect pests but safe for humans and other animals, reducing the need for chemical pesticides.


15.

Assertion (A): Restriction enzymes are used in genetic engineering to cut DNA at specific sequences.
Reason (R): Restriction enzymes recognize specific short sequences of DNA and cleave the DNA molecules at or near these sites.
Answer: (A) Both A and R are true, and R is the correct explanation of A.
Explanation: Restriction enzymes are used to cut DNA at specific sequences, allowing scientists to isolate and manipulate genes in genetic engineering processes.


16.

Assertion (A): Human insulin is produced in genetically modified bacteria.
Reason (R): The gene for human insulin is inserted into Escherichia coli bacteria, which then produce insulin in large quantities.
Answer: (A) Both A and R are true, and R is the correct explanation of A.
Explanation: The human insulin gene is inserted into E. coli using recombinant DNA technology, and the bacteria produce insulin, which is then purified for medical use.


17.

Assertion (A): Biotechnology can be used to develop plants resistant to drought.
Reason (R): Genetic engineering allows the introduction of genes that help plants tolerate water stress and survive in dry conditions.
Answer: (A) Both A and R are true, and R is the correct explanation of A.
Explanation: Biotechnology enables the development of drought-resistant crops by incorporating genes that allow plants to cope with water scarcity.


18.

Assertion (A): Golden rice has been engineered to contain higher levels of vitamin A.
Reason (R): Golden rice contains genes that produce beta-carotene, which is converted into vitamin A in the human body.
Answer: (A) Both A and R are true, and R is the correct explanation of A.
Explanation: Golden rice is genetically modified to produce beta-carotene, a precursor of vitamin A, helping to combat vitamin A deficiency in developing countries.


19.

Assertion (A): Cry proteins from Bacillus thuringiensis are toxic to pests.
Reason (R): Cry proteins are toxic to the gut of certain insects, disrupting their digestive system and killing them.
Answer: (A) Both A and R are true, and R is the correct explanation of A.
Explanation: Cry proteins produced by Bacillus thuringiensis have insecticidal properties and are used in Bt crops to protect them from pests.


20.

Assertion (A): The Polymerase Chain Reaction (PCR) technique requires specific primers to amplify a desired DNA sequence.
Reason (R): Primers are short DNA sequences that provide a starting point for DNA polymerase to begin DNA synthesis during PCR.
Answer: (A) Both A and R are true, and R is the correct explanation of A.
Explanation: In PCR, primers bind to the specific DNA region of interest, allowing DNA polymerase to replicate the target sequence during amplification.


21.

Assertion (A): Gene cloning is a technique used to produce copies of specific genes.
Reason (R): Gene cloning involves inserting the gene of interest into a vector, which is then introduced into a host organism for replication.
Answer: (A) Both A and R are true, and R is the correct explanation of A.
Explanation: Gene cloning involves isolating a gene and inserting it into a vector, which is introduced into a host cell for replication, allowing mass production of the gene.


22.

Assertion (A): Biotechnological applications in agriculture have led to the development of herbicide-resistant crops.
Reason (R): Herbicide-resistant genes are inserted into crops, allowing them to survive herbicide treatment without damage.
Answer: (A) Both A and R are true, and R is the correct explanation of A.
Explanation: Genetic engineering enables the insertion of genes that confer herbicide resistance, allowing crops to thrive even when herbicides are applied to kill weeds.


23.

Assertion (A): PCR is widely used for DNA fingerprinting.
Reason (R): PCR allows for the amplification of specific DNA regions, which can then be analyzed for genetic identification.
Answer: (A) Both A and R are true, and R is the correct explanation of A.
Explanation: PCR amplifies DNA segments that are unique to individuals, enabling DNA fingerprinting for identification purposes in criminal investigations and paternity tests.


24.

Assertion (A): Biotechnology can be used to develop biopesticides.
Reason (R): Biopesticides are derived from natural organisms and are used to control pests without harming the environment.
Answer: (A) Both A and R are true, and R is the correct explanation of A.
Explanation: Biopesticides, such as those produced by Bacillus thuringiensis, are biological control agents that target specific pests, reducing the need for chemical pesticides and minimizing environmental impact.


25.

Assertion (A): Recombinant DNA technology is used to produce human growth hormone.
Reason (R): The gene for human growth hormone is inserted into bacterial plasmids, allowing bacteria to produce the hormone in large quantities.
Answer: (A) Both A and R are true, and R is the correct explanation of A.
Explanation: Recombinant DNA technology enables the production of human growth hormone by inserting the gene into bacteria, which then produce the hormone for medical use.


26.

Assertion (A): Bt crops are engineered to be resistant to pests.
Reason (R): The Bacillus thuringiensis gene inserted into the crops produces proteins that are toxic to specific insect pests.
Answer: (A) Both A and R are true, and R is the correct explanation of A.
Explanation: The gene from Bacillus thuringiensis produces a protein toxic to pests, protecting crops like cotton and corn from insect damage.


27.

Assertion (A): Gene therapy aims to correct genetic disorders by altering defective genes in patients.
Reason (R): Gene therapy involves the transfer of normal genes into a patient’s cells to replace or repair defective genes.
Answer: (A) Both A and R are true, and R is the correct explanation of A.
Explanation: Gene therapy aims to cure genetic disorders by delivering functional copies of genes into a patient's cells to compensate for defective or missing genes.


28.

Assertion (A): Cloning is the process of creating an identical copy of an organism.
Reason (R): Cloning involves transferring the nucleus of a somatic cell into an egg cell, which then develops into an organism genetically identical to the donor.
Answer: (A) Both A and R are true, and R is the correct explanation of A.
Explanation: Cloning creates genetically identical organisms by transferring the nucleus of a somatic cell into an enucleated egg cell, which develops into a clone of the donor organism.


29.

Assertion (A): Microbial fuel cells are an application of biotechnology.
Reason (R): Microbial fuel cells use bacteria to break down organic material and generate electricity.
Answer: (A) Both A and R are true, and R is the correct explanation of A.
Explanation: Microbial fuel cells harness the metabolic activity of bacteria to convert organic waste into electrical energy, representing an innovative application of biotechnology.


30.

Assertion (A): The application of biotechnology in medicine has led to the development of vaccines.
Reason (R): Recombinant DNA technology allows the production of safer and more effective vaccines by introducing antigens into host organisms for immune response.
Answer: (A) Both A and R are true, and R is the correct explanation of A.
Explanation: Biotechnology enables the production of recombinant vaccines, where genes encoding viral antigens are inserted into suitable hosts to induce immune responses.


31.

Assertion (A): Synthetic biology is an emerging field in biotechnology.
Reason (R): Synthetic biology involves designing and constructing new biological parts, devices, and systems that do not exist in nature.
Answer: (A) Both A and R are true, and R is the correct explanation of A.
Explanation: Synthetic biology combines biology, engineering, and computer science to create new synthetic organisms or biological systems for industrial, medical, or environmental purposes.


32.

Assertion (A): Biotechnology is used in the production of biofuels.
Reason (R): Biofuels are derived from renewable biological sources, and biotechnology helps in optimizing microbial processes to produce them efficiently.
Answer: (A) Both A and R are true, and R is the correct explanation of A.
Explanation: Biotechnology facilitates the production of biofuels like ethanol and biodiesel by utilizing microorganisms or enzymes to convert biomass into fuel.


33.

Assertion (A): Recombinant DNA technology is useful in the production of monoclonal antibodies.
Reason (R): Monoclonal antibodies are produced by fusing a specific immune cell with a cancer cell to form hybridomas, which can be cultured for antibody production.
Answer: (A) Both A and R are true, and R is the correct explanation of A.
Explanation: Recombinant DNA technology enables the creation of monoclonal antibodies by using hybridoma cells, which are capable of producing large amounts of a specific antibody.


34.

Assertion (A): The application of biotechnology in food production has led to genetically modified food products.
Reason (R): Genetic modifications in crops can enhance their yield, nutritional value, and resistance to diseases and pests.
Answer: (A) Both A and R are true, and R is the correct explanation of A.
Explanation: Biotechnology is applied in agriculture to create genetically modified crops that have improved traits such as better yield, disease resistance, and enhanced nutritional content.


35.

Assertion (A): Biotechnology has enabled the development of diagnostic kits for detecting diseases.
Reason (R): Diagnostic kits often use antibodies or enzymes to detect specific pathogens or disease markers in biological samples.
Answer: (A) Both A and R are true, and R is the correct explanation of A.
Explanation: Biotechnology plays a key role in developing diagnostic kits that utilize specific biological agents like antibodies or enzymes to detect the presence of pathogens or disease markers.


36.

Assertion (A): Biotechnology is used in agriculture to produce pest-resistant plants.
Reason (R): Genes from Bacillus thuringiensis are introduced into plants to make them resistant to insect pests.
Answer: (A) Both A and R are true, and R is the correct explanation of A.
Explanation: Bt crops are genetically engineered to produce Bacillus thuringiensis toxin, which protects them from specific insect pests without the need for chemical pesticides.


37.

Assertion (A): Biotechnology has contributed to the development of new antibiotics.
Reason (R): Biotechnology techniques like fermentation and genetic engineering help in the production of antibiotics by microorganisms.
Answer: (A) Both A and R are true, and R is the correct explanation of A.
Explanation: Biotechnology has enabled the production of antibiotics by optimizing microbial fermentation processes and using genetic modifications to enhance antibiotic yield.


38.

Assertion (A): Bioinformatics is a critical tool in biotechnology.
Reason (R): Bioinformatics involves the use of computer software to analyze biological data, which aids in understanding genes, proteins, and their functions.
Answer: (A) Both A and R are true, and R is the correct explanation of A.
Explanation: Bioinformatics helps manage and analyze large volumes of biological data, such as genetic sequences, which is essential for advances in biotechnology and medicine.


39.

Assertion (A): Biotechnology is used to develop plants that are resistant to viral diseases.
Reason (R): Biotechnology techniques, like gene silencing, can be used to suppress the expression of viral genes in plants.
Answer: (A) Both A and R are true, and R is the correct explanation of A.
Explanation: Biotechnology, including RNA interference and gene silencing, is used to create plants that are resistant to viral infections by disrupting the viral replication process.


40.

Assertion (A): Enzyme biotechnology plays a major role in industrial applications.
Reason (R): Enzymes from microorganisms are used in various industrial processes such as brewing, baking, and textile processing.
Answer: (A) Both A and R are true, and R is the correct explanation of A.
Explanation: Microbial enzymes are used in industries for processes like fermentation in brewing, baking, and other applications, improving efficiency and sustainability.


41.

Assertion (A): DNA sequencing is essential for the development of personalized medicine.
Reason (R): DNA sequencing helps in identifying genetic variations that influence drug responses, allowing for customized treatments.
Answer: (A) Both A and R are true, and R is the correct explanation of A.
Explanation: DNA sequencing allows for the identification of genetic variations that impact how individuals respond to medications, enabling personalized treatment plans.


42.

Assertion (A): GMOs (Genetically Modified Organisms) are often used in agriculture to improve crop yields.
Reason (R): GMOs are engineered to possess traits such as improved resistance to pests, diseases, and environmental stress.
Answer: (A) Both A and R are true, and R is the correct explanation of A.
Explanation: GMOs are designed to have beneficial traits that increase crop yield by making them more resistant to external stressors, which benefits agricultural productivity.


43.

Assertion (A): Biotechnology applications include the production of insulin for diabetes management.
Reason (R): Recombinant DNA technology is used to produce insulin by inserting the human insulin gene into bacterial cells, which then synthesize the hormone.
Answer: (A) Both A and R are true, and R is the correct explanation of A.
Explanation: Recombinant DNA technology is used to insert the human insulin gene into bacteria, which then produce insulin, a key treatment for diabetes.


44.

Assertion (A): Biotechnology is used to create genetically modified microorganisms for the production of valuable products.
Reason (R): Genetic modification of microorganisms can enhance their ability to produce enzymes, hormones, and other bio-based products.
Answer: (A) Both A and R are true, and R is the correct explanation of A.
Explanation: Genetically engineered microorganisms are often used in biotechnology to produce enzymes, hormones, and other bio-based products in large quantities.


45.

Assertion (A): Biotechnology is used in bioremediation to clean up environmental pollutants.
Reason (R): Certain microorganisms have the ability to degrade harmful pollutants, and biotechnology harnesses these capabilities for environmental cleanup.
Answer: (A) Both A and R are true, and R is the correct explanation of A.
Explanation: Bioremediation utilizes microorganisms to break down and neutralize pollutants in the environment, a process enhanced by biotechnology techniques.


46.

Assertion (A): Biotechnology involves manipulating biological organisms for practical uses.
Reason (R): Biotechnology uses biological processes to develop products and technologies that address various human needs in medicine, agriculture, and industry.
Answer: (A) Both A and R are true, and R is the correct explanation of A.
Explanation: Biotechnology manipulates organisms to develop products that benefit society, including medicines, agricultural products, and environmental solutions.


47.

Assertion (A): Biodegradable plastics can be produced through biotechnology.
Reason (R): Microorganisms can be genetically engineered to produce bioplastics, which are more eco-friendly than conventional plastics.
Answer: (A) Both A and R are true, and R is the correct explanation of A.
Explanation: Biotechnology enables the production of biodegradable plastics by modifying microorganisms to produce plastic-like materials that break down naturally in the environment.


48.

Assertion (A): Biotechnology can be used for the production of therapeutic proteins.
Reason (R): By inserting the gene for a therapeutic protein into a suitable host organism, large quantities of the protein can be produced for medical use.
Answer: (A) Both A and R are true, and R is the correct explanation of A.
Explanation: Recombinant DNA technology is used to insert therapeutic protein genes into hosts like bacteria or yeast, which then produce the proteins in large quantities for medical applications.


49.

Assertion (A): Recombinant DNA technology is central to the production of genetically modified crops.
Reason (R): Recombinant DNA technology allows scientists to transfer specific genes from one organism to another, enhancing desirable traits in crops.
Answer: (A) Both A and R are true, and R is the correct explanation of A.
Explanation: Recombinant DNA technology enables the transfer of genes that confer beneficial traits, such as resistance to pests or enhanced nutritional content, into crops.


50.

Assertion (A): The development of transgenic organisms is a major achievement of biotechnology.
Reason (R): Transgenic organisms contain genes from other species, which give them new traits that were not naturally present in the original organism.
Answer: (A) Both A and R are true, and R is the correct explanation of A.
Explanation: Transgenic organisms are created by introducing genes from other species, giving them new characteristics, which is a key application of biotechnology.