Class 12 Biology Chapter – Biotechnology and Its Applications: Complete Notes with MCQs

Biotechnology is one of the fastest-growing branches of science that uses living organisms, cells, enzymes, and genetic materials to develop products and processes useful for humans. In simple terms, it is the technology of biology.
In Class 12 Biology, the chapter “Biotechnology and Its Applications” highlights how genetic engineering and molecular tools are applied in agriculture, medicine, industry, and environment.

The chapter is extremely important from both academic and competitive exam perspectives (NEET, Board Exams, CUET, etc.) because it covers practical applications of biotechnology. It also raises discussions on ethical issues, biosafety, and patents, making it relevant in modern society.

Table of Contents

Class 12 Biology Chapter – Biotechnology and Its Applications: Complete Notes with MCQs

Major Applications of Biotechnology

1. Biotechnology in Agriculture

Agriculture has been the most important field of biotechnology application because of the growing demand for food. Scientists use transgenic plants to improve yield, nutritional value, resistance to pests, diseases, and tolerance to environmental stresses.

1.1 Transgenic Plants

Definition: Plants that contain foreign DNA introduced by genetic engineering.
Purpose: To improve traits such as productivity, quality, and resistance.
Examples: Bt cotton, Golden Rice, Flavr Savr Tomato.

1.2 Bt Crops – Pest Resistant Plants

Bt (Bacillus thuringiensis) is a soil bacterium producing crystalline proteins toxic to insects.
Bt gene is introduced into plants (like cotton, maize).
When insects such as bollworms feed on Bt cotton, the toxin activates in their gut and kills them.
Advantages:
- Reduced use of chemical pesticides.
- Safe for humans and beneficial insects.

1.3 Herbicide Tolerant Crops

Crops engineered to resist specific herbicides.
Farmers can spray herbicides to kill weeds without harming crops.
Example: Herbicide-resistant soybean.

1.4 Biofortification

Enhancing the nutritional quality of crops.
Examples:
- Golden Rice – rich in Vitamin A.
- Protein-rich maize and iron-fortified rice.
Helps fight malnutrition and hidden hunger.

1.5 Other Agricultural Applications

Development of stress-resistant crops (drought, salinity, cold).
Improved storage quality and shelf life.

2. Biotechnology in Medicine

Medical biotechnology is one of the most impactful areas, helping in disease diagnosis, therapy, and prevention.

2.1 Genetically Engineered Insulin

Earlier, insulin was extracted from pigs and cattle, causing allergic reactions in some patients.
Now, insulin is produced using recombinant DNA technology.
Human insulin gene is inserted into E. coli bacteria → bacteria produce pure human insulin.
Safer, cheaper, and available worldwide.

2.2 Gene Therapy

Technique to treat genetic disorders by replacing faulty genes with normal ones.
Example: Adenosine deaminase (ADA) deficiency – treated by inserting functional ADA gene into patient’s lymphocytes.
Two types:
- Somatic gene therapy (affects only patient).
- Germline gene therapy (heritable, but ethically debated).

2.3 Molecular Diagnosis

Early and accurate diagnosis saves lives. Biotechnology tools used:

PCR (Polymerase Chain Reaction) – detects pathogens even at very early stages.
ELISA (Enzyme-Linked Immunosorbent Assay) – detects antigens or antibodies (used for HIV, Hepatitis).
DNA fingerprinting – for genetic disorders and forensic studies.

2.4 Vaccines

Traditional vaccines (killed/weakened microbes) sometimes unsafe.
Biotechnology allows production of recombinant vaccines (safer and effective).
Example: Hepatitis B vaccine from yeast cells.

2.5 Pharmacogenomics

Personalized medicine using genetic information of patients.
Helps in designing drugs according to individual genetic makeup.

3. Biotechnology in Industry

Industrial biotechnology uses microorganisms and enzymes for large-scale production of useful substances.

3.1 Microbial Production

Antibiotics (penicillin, streptomycin).
Organic acids (citric acid, lactic acid).
Alcoholic beverages (wine, beer) through fermentation.

3.2 Biofuels

Renewable fuels derived from biological sources.
Example: Bioethanol from sugarcane and biogas from waste.

3.3 Enzyme Industry

Enzymes like amylases, proteases, lipases used in detergents, textiles, paper, and food industry.

3.4 Bioplastics

Plastics like PHB (Polyhydroxybutyrate) produced by bacteria.
Environment-friendly alternative to petroleum plastics.

4. Biotechnology in Environmental Management

Biotechnology helps reduce pollution and conserve resources.

4.1 Bioremediation

Microbes used to remove pollutants.
Example: Oil spill degradation by Pseudomonas putida.

4.2 Bio-mining

Use of microbes to extract metals from ores.
Example: Copper extraction by Thiobacillus ferrooxidans.

4.3 Wastewater Treatment

Sewage treatment plants use microbial consortia to recycle organic waste into clean water.

4.4 Biocontrol Agents

Use of natural predators and microbes instead of chemicals.
Example: Trichoderma fungi act against plant pathogens.

5. Ethical Issues and Social Concerns

With great power comes great responsibility. Biotechnology also raises ethical and safety issues.

5.1 Biosafety Concerns

Risk of GMOs spreading unintended genes.
Possibility of “superweeds” or “superbugs.”

5.2 Bioethics

Concerns about human cloning, stem cell research, and germline modifications.
Balance between scientific progress and moral values is essential.

5.3 Intellectual Property Rights (IPR) and Patents

Debate on whether living organisms or genes can be patented.
Example: Patenting of basmati rice genes and neem products faced global opposition.

Summary of Key Concepts

Agriculture: Bt crops, herbicide resistance, biofortification, transgenic plants.
Medicine: Insulin, gene therapy, diagnostics, vaccines, pharmacogenomics.
Industry: Biofuels, enzymes, antibiotics, bioplastics.
Environment: Bioremediation, biomining, sewage treatment, biocontrol.
Ethics: Biosafety, bioethics, patents.

Objective Questions (MCQs) – 35 Questions

1. Who is known as the father of biotechnology?

a) Louis Pasteur
b) Karl Ereky
c) Watson
d) Mendel
Answer: b) Karl Ereky

2. Bt cotton is resistant to:

a) Weeds
b) Insects
c) Viruses
d) Fungi
Answer: b) Insects

3. Which bacterium produces Bt toxin?

a) Rhizobium
b) Pseudomonas
c) Bacillus thuringiensis
d) Agrobacterium
Answer: c) Bacillus thuringiensis

4. Golden Rice is rich in:

a) Vitamin C
b) Vitamin B
c) Vitamin A
d) Vitamin D
Answer: c) Vitamin A

5. The first transgenic crop developed was:

a) Rice
b) Flavr Savr Tomato
c) Wheat
d) Cotton
Answer: b) Flavr Savr Tomato

6. Recombinant insulin is produced by:

a) Yeast
b) Bacteria
c) Fungi
d) Plants
Answer: b) Bacteria

7. ADA deficiency is treated by:

a) Chemotherapy
b) Gene therapy
c) Antibiotics
d) Vaccination
Answer: b) Gene therapy

8. Which technique is used for DNA amplification?

a) PCR
b) ELISA
c) DNA fingerprinting
d) Electrophoresis
Answer: a) PCR

9. ELISA is used to detect:

a) Antibiotics
b) Antigens/Antibodies
c) Hormones
d) Enzymes
Answer: b) Antigens/Antibodies

10. Hepatitis B vaccine is produced by:

a) Yeast cells
b) Viruses
c) Bacteria
d) Fungi
Answer: a) Yeast cells

11. PHB is a type of:

a) Antibiotic
b) Bioplastic
c) Enzyme
d) Biofuel
Answer: b) Bioplastic

12. The bacterium used in bioremediation of oil spills:

a) Rhizobium
b) Pseudomonas
c) Bacillus
d) Clostridium
Answer: b) Pseudomonas

13. Which is a biofortified crop?

a) Normal rice
b) Golden Rice
c) Bt cotton
d) Hybrid maize
Answer: b) Golden Rice

14. The Flavr Savr tomato was engineered for:

a) Pest resistance
b) Longer shelf life
c) Nutritional quality
d) Herbicide tolerance
Answer: b) Longer shelf life

15. ADA stands for:

a) Adenosine Diphosphate
b) Adenosine Deaminase
c) Adenine DNA
d) None
Answer: b) Adenosine Deaminase

16. Who produced the first recombinant DNA molecule?

a) Boyer and Cohen
b) Watson and Crick
c) Jacob and Monod
d) Mendel
Answer: a) Boyer and Cohen

17. Which plant was the first genetically modified in India?

a) Rice
b) Bt Cotton
c) Tomato
d) Brinjal
Answer: b) Bt Cotton

18. Which crop is insect-resistant?

a) Golden Rice
b) Bt cotton
c) Wheat
d) Normal maize
Answer: b) Bt cotton

19. Which disease is linked with gene therapy?

a) Diabetes
b) ADA deficiency
c) Tuberculosis
d) Polio
Answer: b) ADA deficiency

20. The process of improving nutritional quality of food crops is called:

a) Hybridization
b) Biofortification
c) Mutation breeding
d) Genetic drift
Answer: b) Biofortification

21. Which is NOT a product of biotechnology?

a) Insulin
b) Antibiotics
c) Bt toxin
d) Penicillin (naturally discovered)
Answer: d) Penicillin

22. The term “biopiracy” is related to:

a) Theft of biological resources
b) Deforestation
c) Illegal fishing
d) Hunting
Answer: a) Theft of biological resources

23. Intellectual Property Rights are related to:

a) Patents
b) Farming
c) Fishing
d) Forests
Answer: a) Patents

24. DNA fingerprinting is based on:

a) Repetitive DNA sequences
b) PCR only
c) ELISA
d) Antibodies
Answer: a) Repetitive DNA sequences

25. Biocontrol is:

a) Use of chemicals
b) Use of natural organisms to control pests
c) Use of radiation
d) Genetic drift
Answer: b) Use of natural organisms to control pests

26. Example of a biocontrol agent:

a) Trichoderma
b) Agrobacterium
c) E. coli
d) Bacillus
Answer: a) Trichoderma

27. Which plant produces insect-resistant protein naturally?

a) Cotton
b) Bacillus thuringiensis (bacteria, not plant)
c) Neem
d) Rice
Answer: b) Bacillus thuringiensis (bacteria)

28. Which is an example of a recombinant product?

a) Penicillin
b) Insulin
c) Glucose
d) Maltose
Answer: b) Insulin

29. PCR was invented by:

a) Kary Mullis
b) Watson
c) Crick
d) Pauling
Answer: a) Kary Mullis

30. Which of the following is biodegradable plastic?

a) PVC
b) PHB
c) Nylon
d) Polythene
Answer: b) PHB

31. Which technique is used in HIV detection?

a) ELISA
b) PCR
c) Both a & b
d) Electrophoresis
Answer: c) Both a & b

32. Which vaccine is produced by recombinant DNA technology?

a) Polio
b) Hepatitis B
c) Smallpox
d) Rabies
Answer: b) Hepatitis B

33. Which microbe is used in biogas production?

a) Methanogens
b) Cyanobacteria
c) Lactobacillus
d) Pseudomonas
Answer: a) Methanogens

34. Intellectual property rights are meant to:

a) Protect ideas and inventions
b) Encourage piracy
c) Stop farming
d) Stop trade
Answer: a) Protect ideas and inventions

35. Which of the following is NOT an application of biotechnology?

a) Bt cotton
b) Golden Rice
c) Hybrid wheat by normal breeding
d) Recombinant insulin
Answer: c) Hybrid wheat by normal breeding

Short Answer Questions (5)

Q1. Define biotechnology and mention two of its applications.

Answer:
Biotechnology is the use of living organisms, cells, enzymes, or genetic material to develop products and processes for human welfare.
Applications:

In agriculture – production of Bt crops that resist insect pests.
In medicine – production of recombinant insulin for diabetic patients.

Q2. What is biofortification? Give an example.

Answer:
Biofortification is the process of increasing the nutritional quality of crops through genetic engineering or conventional breeding.
Example: Golden Rice enriched with Vitamin A to reduce night blindness.

Q3. What is the principle of PCR?

Answer:
The principle of Polymerase Chain Reaction (PCR) is to amplify (make multiple copies of) a specific DNA sequence using:

DNA polymerase enzyme,
Primers, and
Nucleotides through repeated cycles of denaturation, annealing, and extension.

Q4. Why was recombinant insulin needed instead of animal insulin?

Answer:
Earlier, insulin was extracted from the pancreas of pigs and cattle. This caused:

Allergic reactions in some patients,
Supply limitations, and
Ethical concerns.
Recombinant human insulin, produced using E. coli bacteria, is identical to human insulin, safer, and available in large quantities.

Q5. What is bioremediation? Give one example.

Answer:
Bioremediation is the process of using microorganisms to remove pollutants or toxic waste from the environment.
Example: Pseudomonas putida bacteria are used to clean oil spills.

Long Answer Questions (5)

Q1. Explain the role of biotechnology in agriculture with examples of Bt crops and biofortification.

Answer:
Biotechnology has significantly improved agriculture by enhancing crop productivity, resistance, and nutritional value.

Bt Crops (Pest Resistance):
- Bacillus thuringiensis (Bt) is a bacterium that produces a toxin harmful to insects.
- The Bt gene is inserted into crops like cotton and maize.
- When insect larvae (bollworm, stem borer) eat the crop, the Bt toxin gets activated in their alkaline gut and kills them.
- Example: Bt Cotton in India, which resists bollworm attacks.
- Advantage: Reduces chemical pesticide use, safe for humans, eco-friendly.
Herbicide Resistance:
- Crops can be engineered to tolerate specific herbicides.
- Farmers can kill weeds without harming crops.
Biofortification (Nutritional Improvement):
- Biotechnology increases the nutritional value of food crops.
- Example: Golden Rice enriched with Vitamin A to prevent night blindness.
- Protein-rich maize and iron-enriched rice also developed.

Conclusion:
Biotechnology in agriculture ensures higher yield, pest resistance, and improved nutrition, helping in food security and public health.

Q2. Describe how recombinant DNA technology is used to produce insulin.

Answer:
Insulin is a hormone that regulates blood sugar. Earlier, insulin was obtained from pigs and cattle, which caused allergic reactions.

Steps of recombinant insulin production:

The human insulin gene is identified and isolated.
This gene is inserted into a plasmid vector.
The recombinant plasmid is transferred into E. coli bacteria.
Bacteria are cultured, and they start producing insulin.
The insulin is extracted and purified for medical use.

Features:

Recombinant insulin is identical to natural human insulin.
Safe, effective, and widely used for diabetic patients.

Conclusion:
Recombinant DNA technology solved the shortage of insulin and provided a reliable, ethical, and cost-effective treatment for diabetes.

Q3. Write a note on gene therapy with reference to ADA deficiency.

Answer:
Gene Therapy:

A technique that involves inserting functional genes into a patient’s cells to replace defective ones.
It is used to treat genetic disorders.

Example: ADA Deficiency

ADA (Adenosine Deaminase) is an enzyme essential for the immune system.
Deficiency leads to severe combined immunodeficiency (SCID).
Children with ADA deficiency have weak immunity and suffer frequent infections.

Treatment using Gene Therapy:

Lymphocytes (a type of white blood cell) are isolated from the patient.
A functional ADA gene is introduced into these lymphocytes using a retrovirus vector.
Modified cells are reintroduced into the patient’s body.
The lymphocytes produce ADA enzyme, improving immunity.

Conclusion:
Though temporary (since lymphocytes die), gene therapy is a pioneering step in treating genetic disorders.

Q4. Discuss the ethical issues related to biotechnology.

Answer:
Biotechnology, while beneficial, raises several ethical and social concerns:

Biosafety Issues:
- Risk of genetically modified organisms (GMOs) contaminating natural biodiversity.
- GM crops might create “superweeds” or resistant insects.
Bioethics:
- Use of embryos for stem cell research is controversial.
- Cloning of animals and possibility of human cloning raises moral concerns.
- Gene therapy in germline cells could affect future generations.
Biopiracy:
- Exploitation of biological resources from developing countries without permission or benefit sharing.
- Example: Patenting of neem and basmati rice genes by foreign companies.
Patents and IPR:
- Debate whether life forms, genes, or seeds should be patented.
- Could make farmers dependent on multinational companies.

Conclusion:
Ethical guidelines, strict biosafety measures, and fair sharing of resources are essential to balance progress and social responsibility in biotechnology.

Q5. Explain the role of biotechnology in environmental protection with examples.

Answer:
Biotechnology plays an important role in conserving the environment and managing pollution.

Bioremediation:
- Use of microbes to degrade pollutants and toxins.
- Example: Pseudomonas putida cleans oil spills.
Biomining:
- Microbes extract metals from ores in an eco-friendly way.
- Example: Thiobacillus ferrooxidans used for copper extraction.
Sewage and Waste Treatment:
- Microbial consortia in sewage treatment plants recycle organic waste into clean water and biogas.
Biodegradable Plastics:
- Plastics like PHB (Polyhydroxybutyrate) are produced by bacteria.
- They are eco-friendly alternatives to petroleum plastics.
Biocontrol Agents:
- Natural predators and microbes control pests, reducing pesticide use.
- Example: Trichoderma fungi act against plant pathogens.

Conclusion:
By using natural biological processes, biotechnology reduces dependence on harmful chemicals and provides sustainable solutions for environmental conservation.

FAQs on Biotechnology and Its Applications

Q1: What are Bt crops?

Answer: Crops genetically modified with Bacillus thuringiensis (Bt) gene, which produces toxin proteins that kill insect pests. Example: Bt cotton.

Q2: What is gene therapy?

Answer: A medical technique that corrects defective genes by introducing functional ones. Example: Treatment of ADA deficiency.

Q3: Give two examples of biofortified crops.

Answer: Golden Rice (Vitamin A enriched) and Iron-fortified rice.

Q4: How is insulin produced by biotechnology?

Answer: By inserting human insulin gene into E. coli bacteria, which then produce pure human insulin.

Q5: What is bioremediation?

Answer: Use of microorganisms to clean pollutants such as oil spills and heavy metals from the environment.

Conclusion

The chapter “Biotechnology and Its Applications” shows how science is solving global challenges in food security, healthcare, industry, and environmental conservation. From Bt cotton to recombinant insulin, biotechnology has changed the world drastically. At the same time, we must ensure responsible use by considering bioethics, biosafety, and social welfare.

For Class 12 students, this chapter is both conceptual and application-oriented, making it essential for board exams and entrance exams like NEET. Understanding it not only helps in exams but also provides awareness of the future of science and humanity.

Follow My Insta I’d