Biotechnology and Its Applications – Revision Notes, Key Concepts & Important Questions

Biotechnology and Its Applications is an important chapter in Class 12 Biology. The chapter explains how living organisms, cells, and genetic material are used to produce valuable products in agriculture, medicine, and industry. The topics covered include genetically modified crops (Bt technology, RNA interference), recombinant insulin, gene therapy, molecular diagnostics like PCR and ELISA, transgenic animals, and ethical issues such as biopiracy and GEAC regulations.

These revision notes on Biotechnology and Its Applications crafted by ALLEN’s subject experts provide a quick overview of key concepts, important terms, and real-world uses in medicine, agriculture, and industry. Designed for last-minute preparation, they help students revise efficiently and strengthen exam-ready understanding.

1.0Concept-Wise Important Revision Notes

1. What is Biotechnology? 

Biotechnology is the use of living organisms or their derivatives to develop useful products and processes. 

2. What are the key areas of application of Biotechnology?

The key applications of Biotechnology are:

• Therapeutics - Production of medicines and recombinant products.
• Diagnostics - Detection of diseases using molecular techniques.
• Genetically Modified Crops - Development of pest-resistant and stress-tolerant crops.
• Processed Food - Improvement of food quality and shelf life.
• Bioremediation & Waste Treatment - Use of microbes to clean pollutants.
• Energy Production - Biological methods for sustainable energy generation.

3. What are the three critical areas of research in Biotechnology?

1. Development of improved organisms (microbes or enzymes) as catalysts.
2. Creating optimal engineering conditions for the effective functioning of catalysts.
3. Downstream processing for the purification of protein/organic compounds.

4. Important Applications of Biotechnology: Agriculture, Medicine

Biotechnology finds applications in various fields, including agriculture, medicine, and production of transgenic animals.

1. Applications of Biotechnology in Agriculture

Food production can primarily be increased using 3 methods, namely:

• Agrochemical-based agriculture
• Organic agriculture
• Genetically engineered crop-based agriculture

Plant Tissue Culture

Micropropagation

• Rapid production of thousands of genetically identical plants (somaclones).
• Used for crops like tomato, banana, and apple.

Meristem Culture

• Virus-free plants are obtained by growing meristem tissue in vitro.
• Applied in banana, sugarcane, and potato.

Somatic Hybridisation

• Cell walls are removed using enzymes (pectinase and cellulase).
• Protoplasts of two species were fused using fusogens.
• Fused product (heterokaryon) cultured to regenerate plantlets.

Genetic Engineering in Agriculture

Genetically Modified Organisms (GMOs): Organisms whose genes are altered to provide beneficial traits such as:

• Abiotic stress tolerance
• Pest resistance
• Reduced post-harvest losses
• Efficient mineral usage
• Enhanced nutritional value (e.g., Vitamin A–enriched rice)
• Industrial resource production

Insect-Resistant Plants – Bt Technology

• Bt toxin produced by Bacillus thuringiensis.
• Cry genes introduced into plants for insect resistance.
• Target-specific against Lepidopterans, Coleopterans, and Dipterans.

Mechanism: Inactive protoxin → Activated in insect gut → Binds midgut cells → Forms pores → Cell lysis → Insect death.

Pest-Resistant Plants – RNA Interference (RNAi)

• RNAi silences specific mRNA using complementary double-stranded RNA.
• Used against nematode Meloidegyne incognitia in tobacco plants.

Process: Sense and antisense RNA → dsRNA formation → mRNA silencing → Parasite cannot survive → Plant protected.

b. Applications of Biotechnology in Medicine

i. Recombinant Therapeutics: Around 30 recombinant therapeutics have been approved globally; 12 are marketed in India.

ii. Genetically Engineered Insulin

• Earlier, insulin extracted from cattle and pigs caused allergic reactions.
• Human insulin consists of A and B chains linked by disulphide bonds.
• Produced by inserting the A and B chain genes into E. coli.
• Chains are produced separately and combined to form mature insulin.
• The first recombinant insulin was produced in 1983 by Eli Lilly.

iii. Gene Therapy

• The method to correct defective genes by introducing a functional gene is called gene therapy.
• The first clinical gene therapy (1990) was used to treat a 4-year old girl with ADA deficiency.

iv. Molecular Diagnosis

PCR

• Detects low levels of bacterial or viral DNA.
• Used for HIV detection, cancer mutation analysis, and genetic disorders.

Autoradiography

• Uses a radioactive probe to detect complementary DNA sequences.
• Mutated genes fail to hybridise with the probe.

ELISA

• Based on antigen-antibody interaction.
• Detects infection by identifying antigens or antibodies.

5. What are Transgenic Animals? What are its Uses?

• Animals with manipulated DNA to express foreign genes.
• Over 95% are mice; others include rats, rabbits, pigs, sheep, cows, and fish.

Uses of Transgenic Animals

• Study of Normal Physiology – Understanding gene regulation and growth factors.
• Disease Models – Research on cancer, cystic fibrosis, rheumatoid arthritis, Alzheimer’s.
• Biological Products – Production of therapeutic proteins (e.g., α-1-antitrypsin).
• Example: Transgenic cow Rosie produced protein-enriched milk.
• Vaccine Safety Testing – Used in polio vaccine testing.
• Chemical Toxicity Testing – More sensitive to toxic substances for faster results.

6. Ethical issues in Biotechnology

Ethical issues in biotechnology include concerns about the safety of genetically modified organisms (GMOs), potential harm to biodiversity and human health, misuse of genetic information, and biopiracy.

The Indian Government has set up organisations such as GEAC (Genetic Engineering Approval Committee) to make decisions regarding the validity of GM research and the safety of introducing GM-organisms for public services.

Biopiracy

• It is the unauthorised use of biological resources without compensation.
• Some of the cases include Basmati rice, Neem, and Turmeric.

Biopiracy of Basmati:

Basmati rice is prized for its distinct aroma and flavour, with 27 documented varieties grown in India out of nearly 200,000 rice varieties. In 1997, a US company secured patent rights through the US Patent and Trademark Office for a “new” semi-dwarf Basmati variety derived from traditional Indian farmer varieties, claiming it as a novel invention.

2.0Memory Tricks

Here are some memory tricks to remember core concepts from the chapter Biotechnology and its applications

Applications of Biotechnology – “TD-GPB-E”

T D G P B E

• T – Therapeutics
• D – Diagnostics
• G – Genetically Modified Crops
• P – Processed Food
• B – Bioremediation
• E – Energy Production

Three Critical Areas of Biotechnology – “COD”

• C – Catalyst (Improved organism/enzyme)
• O – Optimal conditions (Bioreactor/engineering setup)
• D – Downstream processing

Molecular Diagnosis – “PEA detects disease”

• P – PCR
• E – ELISA
• A – Autoradiography

3.0Biotechnology Previous Year Solved Questions

Question 1: Polymerase chain reaction (PCR) amplifies DNA following the equation.

(1) Nⁿ

(2) 2ⁿ

(3) 2n + 1

(4) 2Nⁿ

Answer: (2)

Question 2: Given below are two statements:

Statement I: Transfer RNAs and ribosomal RNAs do not interact with mRNA.
Statement II: RNA interference (RNAi) takes place in all eukaryotic organisms as a method of cellular defence.

In the light of the above statements, choose the most appropriate answer from the options given below:

(1) Both Statement I and Statement II are correct
(2) Both Statement I and Statement II are incorrect
(3) Statement I is correct but Statement II is incorrect
(4) Statement I is incorrect but Statement II is correct

Answer: (4)

Question 3: Which of the following genetically engineered organisms was used by Eli Lilly to prepare human insulin?

(1) Bacterium
(2) Yeast
(3) Virus
(4) Phage

Answer: (1)

Question 4: Given below are two statements:

Statement I: The DNA fragments extracted from gel electrophoresis can be used in construction of recombinant DNA.
Statement II: Smaller size DNA fragments are observed near anode while larger fragments are found near the wells in an agarose gel.

In the light of the above statements, choose the most appropriate answer from the options given below:

(1) Both Statement I and Statement II are correct
(2) Both Statement I and Statement II are incorrect
(3) Statement I is correct but Statement II is incorrect
(4) Statement I is incorrect but Statement II is correct

Answer: (1)

Question 5: Silencing of specific mRNA is possible via RNAi because of –

(1) Complementary dsRNA
(2) Inhibitory ssRNA
(3) Complementary tRNA
(4) Non-complementary ssRNA

Answer: (1)

Question 6: The blue and white selectable markers have been developed which differentiate recombinant colonies from non-recombinant colonies on the basis of the ability to produce colour in the presence of chromogenic substrate.

Given below are two statements about this method:

Statement I: The blue coloured colonies have DNA insert in the plasmid and they are identified as recombinant colonies.
Statement II: The colonies without blue colour are recombinant colonies.

In the light of the above statements, choose the most appropriate answer from the options given below:

(1) Both Statement I and Statement II are correct
(2) Both Statement I and Statement II are incorrect
(3) Statement I is correct but Statement II is incorrect
(4) Statement I is incorrect but Statement II is correct

Answer: (4)