NCERT Exemplar for Chapter 12 Class 12 Biology Biotechnology and its Applications 

NCERT Exemplar for Class 12 Biology allows students to go through the in-depth Biotechnology and its Application. This provided exemplar by SimplyAcad helps students to cover all the areas and sections contained in the chapter 12 of the biology textbook. The exemplar includes different patterns of questions, such as MCQs, very short, short, and long answer types, ensuring that learners engage with all formats effectively and prepare thoroughly for the toughest questions on the paper. Students can easily access this NCERT exemplar for class 12 biology biotechnology and its applications in this article below to perform incredibly well in their upcoming 12th board examinations. There are several NCERT exemplar for class 12 science of all the chapters provided in a detailed manner. Simplyacad made this easy for you.

Access the NCERT Exemplar Class 12 biology biotechnology and its application 

1. Multiple Choice Questions:

Question 1:

Bt cotton is not:

• (a) A GM plant
• (b) Insect-resistant
• (c) A bacterial gene expressing system
• (d) Resistant to all pesticides

Solution:
Option (d) is the answer.

Question 2:

C-peptide of human insulin is:

• (a) A part of mature insulin molecule
• (b) Responsible for the formation of disulphide bridges
• (c) Removed during maturation of pro-insulin to insulin
• (d) Responsible for its biological activity

Solution:
Option (c) is the answer.

Question 3:

GEAC stands for:

• (a) Genome Engineering Action Committee
• (b) Ground Environment Action Committee
• (c) Genetic Engineering Approval Committee
• (d) Genetic and Environment Approval Committee

Solution:
Option (c) is the answer.

Question 4:

α -1 antitrypsin is:

• (a) An antacid
• (b) An enzyme
• (c) Used to treat arthritis
• (d) Used to treat emphysema

Solution:
Option (d) is the answer.

Question 5:

A probe which is a molecule used to locate homologous sequences in a mixture of DNA or RNA molecules, could be:

• (a) An ssRNA
• (b) An ssDNA
• (c) Either RNA or DNA
• (d) Can be ssDNA but not ssRNA

Solution:
Option (c) is the answer.

Question 6:

Choose the correct option regarding Retrovirus:

• (a) An RNA virus that synthesises DNA during infection
• (b) A DNA virus that synthesises RNA during infection
• (c) An ssDNA virus
• (d) A dsRNA virus

Solution:
Option (a) is the answer.

Question 7:

The site of production of ADA in the body is:

• (a) Erythrocytes
• (b) Lymphocytes
• (c) Blood plasma
• (d) Osteocytes

Solution:
Option (b) is the answer.

Question 8:

A protoxin is:

• (a) A primitive toxin
• (b) A denatured toxin
• (c) The toxin produced by protozoa
• (d) Inactive toxin

Solution:
Option (d) is the answer.

Question 9:

Pathophysiology is the:

• (a) Study of physiology of pathogen
• (b) Study of the normal physiology of host
• (c) Study of altered physiology of host
• (d) None of the above

Solution:
Option (c) is the answer.

Question 10:

The trigger for activation of the toxin of Bacillus thuringiensis is:

• (a) Acidic pH of stomach
• (b) High-temperature
• (c) Alkaline pH of gut
• (d) Mechanical action in the insect gut

Solution:
Option (c) is the answer.

Very Short Answer Type Questions Ncert Exemplar Class 12 Biology Biotechnology and its Applications

Question 1:

In view of the current food crisis, it is said that we need another green revolution. Highlight the major limitations of the earlier green revolution.

Solution:

• The earlier green revolution was not beneficial for poor farmers due to the high cost of HYV seeds and pesticides.
• It primarily focused on food grains, particularly wheat and rice.
• The high-yielding variety (HYV) crops required additional water and fertilizers to produce high yields.

Question 2:

Expand GMO. How is it different from a hybrid?

Solution:

• GMO stands for Genetically Modified Organism.
• Hybrids are produced by crossbreeding two different species, while GMOs involve the insertion of a specific gene into an organism to express a desired trait.

Question 3:

Differentiate between diagnostics and therapeutics. Give one example for each category.

Solution:

• Diagnostics involve detecting diseases, such as using ELISA for HIV detection.
• Therapeutics involve treating diseases, such as using Ampicillin to treat bacterial infections.

Question 4:

Give the full form of ELISA. Which disease can be detected using it? Discuss the principle underlying the test.

Solution:

• ELISA stands for Enzyme-Linked Immunosorbent Assay.
• It is used to detect diseases like HIV, Hepatitis B, and Hepatitis C.
• The principle involves the use of an enzyme-linked antigen or antibody to detect the presence of a specific antigen or antibody in a sample.

Question 5:

Can a disease be detected before its symptoms appear? Explain the principle involved.

Solution:

• Yes, diseases can be detected before symptoms appear using techniques like PCR (Polymerase Chain Reaction) that amplify specific DNA sequences to identify pathogens early.

Question 6:

Write a short note on Biopiracy highlighting the exploitation of developing countries by developed countries.

Solution:

• Biopiracy refers to the unauthorized and unethical use of biological resources from developing countries by multinational companies, often without compensation or recognition.

Question 7:

Many proteins are secreted in their inactive form. This is also true of many toxic proteins produced by microorganisms. Explain how the mechanism is useful for the organism producing the toxin.

Solution:

• The mechanism allows the toxin to be activated only under specific conditions, such as changes in pH or temperature, protecting the microorganism from self-harm until it is inside the host.

Question 8:

While creating genetically modified organisms, genetic barriers are not respected. How can this be dangerous in the long run?

Solution:

• It can lead to the creation of unintended organisms that may disrupt ecosystems and food chains, causing long-term environmental and ecological damage.

Question 9:

Why has the Indian Parliament cleared the second amendment of the country’s patent bill?

Solution:

• To prevent the exploitation of bio-resources and traditional knowledge by foreign entities without proper authorization and benefit-sharing.

Question 10:

Give any two reasons why the patent on Basmati should not have gone to an American Company.

Solution:

• Basmati rice is an indigenous variety of India and has been traditionally cultivated for centuries.
• The patent was based on a cross involving the Indian Basmati variety, which should not be patented by a foreign entity.

Short Answer Type Questions Ncert Exemplar Class 12 Biology Biotechnology and its Applications 

Question 1:

Gene expression can be controlled with the help of RNA. Explain the method with an example.

Solution: Gene expression can be controlled using RNA interference (RNAi), where a gene is “knocked out” by degrading the specific mRNA using complementary double-stranded RNA (dsRNA). This inhibits the translation process. For example, the Agrobacterium vector forms complementary dsRNA with nematode genes, silencing them to prevent nematode infection in plants.

Question 2:

Ignoring our traditional knowledge, can we prove costly in the area of biological patenting? Justify.

Solution: Yes, ignoring traditional knowledge can be costly because India, rich in biodiversity, may have its resources exploited by developed countries without proper patenting laws. This could lead to the loss of valuable genetic resources and indigenous knowledge without fair compensation.

Question 3:

Highlight any four areas where genetic modification of plants has been useful.

Solution:

• Abiotic Stress Resistance: GM plants can resist extreme climate conditions, such as drought and salinity.
• Pest Resistance: GM plants like Bt cotton are resistant to pests, reducing the need for chemical pesticides.
• Improved Nutritional Content: GM crops can be engineered to have higher nutritional value, such as rice fortified with vitamin A (Golden Rice).
• Higher Yield: GM plants often produce more yield compared to non-GM crops, contributing to food security.

Question 4:

What is a recombinant DNA vaccine? Give two examples.

Solution: Recombinant DNA vaccines are vaccines created by inserting a gene encoding an antigen from a pathogen into a plasmid vector, which is then introduced into a host to stimulate an immune response. Examples include the Hepatitis B vaccine and the HPV vaccine.

Question 5:

Why is it that the line of treatment for a genetic disease is different from infectious diseases?

Solution: Genetic diseases require treatment that targets the underlying genetic defect, often through gene therapy, which modifies the genome itself. In contrast, infectious diseases are caused by pathogens and are typically treated with medications like antibiotics or antivirals that target the pathogen.

Question 6:

Discuss briefly how a probe is used in molecular diagnostics.

Solution: A probe in molecular diagnostics is a labeled fragment of DNA or RNA used to detect the presence of complementary sequences in a sample. The probe binds to its target sequence, and the label allows for visualization, making it possible to identify specific genes or mutations.

Question 7:

Who was the first patient who was given gene therapy? Why was the given treatment recurrent in nature?

Solution: The first patient to receive gene therapy was a four-year-old girl with adenosine deaminase (ADA) deficiency. The treatment was recurrent because the introduced ADA gene in her lymphocytes was not immortal, necessitating repeated treatments to maintain sufficient enzyme levels.

Question 8:

Taking examples under each category, discuss upstream and downstream processing.

Solution:

• Upstream Processing: Involves the preparation and culturing of the biological material. Example: Fermentation of microorganisms to produce insulin.
• Downstream Processing: Involves the purification, quality control, and formulation of the final product. Example: Purification and formulation of insulin after fermentation.

Question 9:

Define Antigen and Antibody. Name any two diagnostic kits based on them.

Solution:

• Antigen: A foreign substance that induces an immune response in the body, especially the production of antibodies.
• Antibody: A protein produced by the immune system that binds to a specific antigen to neutralize it.
• Examples of diagnostic kits: ELISA (for detecting HIV) and Pregnancy test kits.

Question 10:

ELISA technique is based on the principles of antigen-antibody interaction. Can this technique be used in the molecular diagnosis of a genetic disorder, such as phenylketonuria?

Solution: Yes, ELISA can be used to detect phenylketonuria by identifying the presence or absence of the enzyme responsible for metabolizing phenylalanine. If the enzyme-antibody complex is absent, it indicates the presence of phenylketonuria.

Question 11:

How is a mature, functional insulin hormone different from its prohormone form?

Solution: Proinsulin consists of three chains: A, B, and C. In the mature insulin hormone, the C-peptide is removed, and the A and B chains are linked by disulfide bonds, forming the active insulin molecule.

Question 12:

Gene therapy is an attempt to correct a genetic defect by providing a normal gene to the individual. By this, the normal function can be restored. An alternate method would be to provide the gene product (protein/enzyme) known as enzyme replacement therapy, which would also restore the function. Which, in your opinion, is a better option? Give a reason for your answer.

Solution: Gene therapy is considered a better option because it has the potential to correct the genetic defect at its source, providing a more permanent solution. Enzyme replacement therapy, while effective, often requires ongoing treatments.

Question 13:

Transgenic animals are the animals in which a foreign gene is expressed. Such animals can be used to study the fundamental biological process, a phenomenon, as well as for producing products useful for mankind. Give one example for each type.

Solution:

• Biological Process Study: Transgenic mice are used to study the effects of human genes.
• Product Production: Transgenic goats producing spider silk protein in their milk for use in creating strong, lightweight materials.

Question 14:

When a foreign DNA is introduced into an organism, how is it maintained in the host and how is it transferred to the progeny of the organism?

Solution: The foreign DNA is integrated into the host genome using DNA ligase, ensuring it replicates along with the host’s DNA during cell division. It is passed on to progeny through reproduction.

Question 15:

Bt cotton is resistant to pests, such as lepidopteran, dipterans, and coleopterans. Is Bt cotton also resistant to other pests as well?

Solution: No, Bt cotton is specifically engineered to target lepidopteran, dipterans, and coleopterans and may not be effective against other pests.

Long Answer Type Questions Ncert Exemplar Class 12 Biology Biotechnology and its Applications 

Question 1:

A patient is suffering from ADA deficiency. Can he be cured? How?

Solution: ADA (adenosine deaminase) deficiency is a genetic disorder caused by the deletion of the gene responsible for synthesizing the ADA enzyme, leading to a compromised immune system. There are several approaches to treating this deficiency:

• Bone Marrow Transplantation: This method replaces the defective immune cells with healthy ones from a donor. However, finding a compatible donor is challenging, and there is a risk of the body rejecting the transplanted cells.
• Enzyme Replacement Therapy: This involves injecting the patient with the ADA enzyme extracted from other sources. While this provides temporary relief, it is not a permanent cure and requires lifelong treatment.
• Gene Therapy: This method involves inserting a functional ADA gene into the patient’s cells, particularly lymphocytes, through a vector (usually a virus). The modified lymphocytes are then reintroduced into the patient’s body, where they produce the ADA enzyme. If this gene therapy is performed at an early stage, such as in embryos, it can provide a permanent cure for ADA deficiency.

Question 2:

Define transgenic animals. Explain in detail any four areas where they can be utilized.

Solution: transgenic animals carry and express a foreign gene, known as a transgene, that scientists have genetically modified. Researchers create these animals by using recombinant DNA technology, inserting a gene from one organism into the genome of another.

Areas of Utilization:

Biological Studies:
Researchers use transgenic animals to study gene function and regulation. By introducing or knocking out specific genes, they can observe the effects on the organism, which helps in understanding gene behavior, development processes, and disease mechanisms.

Increased Yield Production:
Scientists engineer transgenic animals to produce more milk, meat, or wool. For instance, cows have been genetically modified to yield milk with higher protein content, and sheep have been altered to produce more wool.

Testing and Clinical Trials:
Transgenic animals act as models for testing the safety and efficacy of new drugs and treatments. These animals can be engineered to express human diseases, allowing researchers to study disease progression and evaluate potential therapies in a living system.

Disease Study and Chemical Safety Testing:
Researchers rely on transgenic animals to study diseases such as cancer, diabetes, and Alzheimer’s. By introducing specific genes associated with these diseases, they can explore the disease’s pathology and develop targeted treatments. Additionally, transgenic animals are used in toxicology to test the safety of chemicals and environmental pollutants.

Question 3:

You have identified a useful gene in bacteria. Make a flow chart of the steps that you would follow to transfer this gene to a plant.

Solution:

Isolation of the Useful Gene:
Restriction endonuclease enzymes cut the bacterial DNA, allowing scientists to isolate the gene of interest.

Insertion into a Vector:
Scientists insert the isolated gene into a suitable vector, such as a plasmid, to create a recombinant DNA molecule.

Transfer of the Recombinant DNA:
Researchers introduce the recombinant DNA into plant cells using methods like Agrobacterium-mediated transformation or a gene gun.

Screening and Selection:
Scientists identify and select the plant cells that have successfully taken up the recombinant DNA through markers or antibiotic resistance.

Regeneration of Transgenic Plants:
The selected cells are cultured to regenerate into whole plants, which will carry and express the introduced gene, making them transgenic.

Question 4:

Highlight five areas where biotechnology has influenced our lives.

Solution: Biotechnology has made significant contributions across various sectors, improving health, agriculture, and environmental sustainability.

Therapeutics and Diagnostic Tools:
Biotechnology revolutionizes medicine with advancements like gene therapy, treating genetic disorders, and rDNA technology, enabling the production of human insulin and other hormones. PCR (Polymerase Chain Reaction) detects diseases at early stages.

Genetically Modified Plants and Animals:
Biotechnology develops GM crops like Bt cotton, which resist pests and yield more. Transgenic animals, engineered to produce more milk or wool, enhance agricultural productivity.

Forensic and Paternity Testing:
Techniques like DNA fingerprinting, developed through biotechnology, solve criminal cases and determine biological relationships in paternity testing.

Wastewater Treatment:
Biotechnology uses microorganisms to treat wastewater, breaking down organic waste, reducing pollution, and making water safe for release into the environment.

Energy Production:
Biotechnology plays a role in producing biofuels, sustainable alternatives to fossil fuels. Microorganisms are engineered to produce ethanol or biogas, contributing to cleaner energy sources.

Question 5:

What are the various advantages of using genetically modified plants to increase the overall yield of the crop?

Solution: Genetically modified (GM) plants offer several advantages that contribute to higher crop yields and enhanced agricultural productivity.

Resistance to Abiotic Stresses:
Scientists engineer GM plants to withstand extreme climate conditions like drought, salinity, and temperature variations. These plants can thrive in environments where traditional crops would fail.

Pest and Disease Resistance:
GM crops, such as Bt cotton, resist pests and diseases, which reduces the need for chemical pesticides and minimizes crop losses.

Improved Nutritional Content:
Biofortified GM plants offer higher levels of essential nutrients like vitamins and minerals. For example, Golden Rice provides increased vitamin A, helping to address nutrient deficiencies in populations that rely heavily on rice as a staple food

Higher Yield and Productivity:
GM crops often produce more food per hectare than non-GM varieties, contributing significantly to food security.

Longer Shelf Life:
Genetic modifications can extend the shelf life of fruits and vegetables, reducing food waste and ensuring that fresh produce stays available for longer periods.

Question 6:

Explain with the help of one example how genetically modified plants can:

(a) Reduce the usage of chemical pesticides

(b) Enhance the nutritional value of food crops

Solution:

(a) Reduce the usage of chemical pesticides:

• An example is Bt cotton, which is genetically modified to express the Bt toxin from the bacterium Bacillus thuringiensis. This toxin is harmful to specific pests, such as the cotton bollworm, but is safe for humans and other non-target organisms. As a result, farmers using Bt cotton need fewer chemical pesticides, reducing environmental impact and production costs.

(b) Enhance the nutritional value of food crops:

• Golden Rice is a transgenic variety of rice that has been engineered to produce beta-carotene, a precursor of vitamin A. By incorporating a gene from the daffodil plant, scientists have enhanced the nutritional value of rice, addressing vitamin A deficiency in populations where rice is a dietary staple.

Ncert Exemplar For Class 12 Science

Students must practise these additional questions for their own benefits, the ncert exemplar are curated by the best subject-matter experts to boost your knowledge on the presented topic. Students can easily access the ncert exemplar for class 12 science by visiting our website SimplyAcad and solve all the questions listed to secure maximum marks. 

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