Biotechnology and its Applications — Previous Year Questions (Class 12 Biology)
Biotechnology harnesses biological processes to produce useful products. This chapter explores genetic engineering, applications in medicine, agriculture,
TL;DR: Biotechnology harnesses biological processes to produce useful products. This chapter explores genetic engineering, applications in medicine, agricult…
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Biotechnology harnesses biological processes to produce useful products. This chapter explores genetic engineering, applications in medicine, agriculture,
Biotechnology and its Applications — Previous Year Questions with Solutions
Q (2023, 4 marks): Define biotechnology. Explain traditional and modern biotechnology with examples.
Answer: Biotechnology:
Definition - Technology that uses living organisms or their products to make or modify products for practical applications.
Traditional Biotechnology:
1. Fermentation:
- Production of yogurt, cheese
- Brewing and baking
- Alcohol production
2. Composting:
- Decomposition of organic matter
- Production of fertilizers
3. Antibiotic Production:
- Penicillin from Penicillium
- Vaccines from microorganisms
Examples: Cheese making, bread baking, wine production (used for centuries)
Modern Biotechnology:
1. Genetic Engineering:
- Direct manipulation of genes
- Creating transgenic organisms
- Gene therapy
2. DNA Recombination:
- Combining DNA from different sources
- Creating new gene combinations
3. Cell and Tissue Culture:
- Growing cells outside organism
- Producing vaccines
4. Microbial Genetics:
- Using microorganisms as factories
- Insulin production
Examples: Bt cotton, genetically modified crops, production of human insulin
Q (2022, 5 marks): Explain the process of genetic engineering and the role of restriction enzymes.
Answer: Genetic Engineering:
Definition - Technique of removing genes from one organism and inserting into another.
Process:
1. Gene Isolation:
- Identify desired gene
- Extract DNA containing gene
- Isolate gene using restriction enzymes
2. Gene Cloning:
- Insert isolated gene into vector
- Multiply gene copies
- Create more copies for study/use
3. Gene Transfer:
- Introduce gene into target organism
- Methods: Microinjection, electroporation, biolistics
4. Integration and Expression:
- Gene integrates into chromosome
- Produces desired protein
- Manifests desired trait
Role of Restriction Enzymes:
1. Function:
- Cut DNA at specific recognition sequences
- Create sticky ends (cohesive ends)
- Allow insertion of foreign DNA
2. Examples:
- EcoRI: Recognizes GAATTC sequence
- BamHI: Recognizes GGATCC sequence
3. Advantages:
- Precise cutting at specific sites
- Produces compatible sticky ends
- Enables controlled DNA recombination
Q (2021, 4 marks): What is a transgenic organism? Explain with three examples of genetically modified crops.
Answer: Transgenic Organism:
Definition - Organism containing foreign DNA (genes) integrated into its genome.
Characteristics:
1. Contains genes from different species
2. Shows new traits from foreign genes
3. Trait passed to offspring
4. Heritable modification
Examples of Genetically Modified Crops:
1. Bt Cotton:
- Contains Bacillus thuringiensis (Bt) gene
- Produces Bt toxin
- Kills lepidopteran pests (bollworm)
- Reduces pesticide use
- Higher yield
2. Bt Corn:
- Resistant to corn borer
- Produces its own insecticide
- Reduces pesticide application
- Cost-effective
3. Golden Rice:
- Contains beta-carotene (Vitamin A precursor)
- Fortified with iron
- Addresses vitamin A deficiency
- Golden color from beta-carotene
- Helps malnutrition in developing countries
4. Herbicide-Resistant Crops:
- Contain resistance genes
- Tolerate specific herbicides
- Enable weed control
- Examples: Roundup Ready soy
Advantages:
- Increased yield
- Reduced pesticide use
- Disease resistance
- Nutritional improvement
Q (2023, 5 marks): Explain the applications of biotechnology in medicine and healthcare.
Answer: Applications of Biotechnology in Medicine:
1. Production of Therapeutic Proteins:
- Human insulin production:
- Genetically modified bacteria produce insulin
- Solves insulin shortage
- Cost-effective
- Human growth hormone (HGH):
- Treatment for growth disorders
- Interferon and interleukin:
- Immune system boosters
- Cancer treatment
2. Gene Therapy:
- Treatment of genetic disorders
- Replacing defective genes
- Examples: Cystic fibrosis, sickle cell disease
- Somatic gene therapy (body cells)
- Germline therapy (controversial)
3. Vaccine Production:
- Genetically engineered vaccines
- Recombinant vaccines
- Safer than live attenuated vaccines
- Examples: Hepatitis B vaccine, HPV vaccine
4. Diagnostics:
- DNA fingerprinting
- Prenatal diagnosis
- Disease detection
- Genetic screening
5. Organ and Tissue Engineering:
- Tissue culture for transplants
- Artificial organs development
- Reduces organ shortage
6. Personalized Medicine:
- Pharmacogenomics
- Treatment tailored to individual genetics
- Improved drug effectiveness
7. Monoclonal Antibodies:
- Targeted cancer therapy
- Autoimmune disease treatment
- Precise targeting of cells
Q (2022, 4 marks): What is CRISPR technology? Explain how it works and its potential applications.
Answer: CRISPR Technology:
Full form - Clustered Regularly Interspaced Short Palindromic Repeats
Origin:
- Bacterial immune system
- Fights viral infections
- Derived from Streptococcus pyogenes
How It Works:
1. Components:
- Cas9 protein: Molecular scissors
- Guide RNA: Directs cutting
- DNA template: Provides replacement sequence
2. Mechanism:
- Guide RNA leads Cas9 to target DNA
- Cas9 cuts both DNA strands
- Cell machinery repairs break
- New gene inserted or old gene disabled
3. Process:
- Precise targeting
- Efficient editing
- Less time-consuming than traditional methods
Potential Applications:
1. Genetic Disease Treatment:
- Sickle cell anemia
- Cystic fibrosis
- Hemophilia
2. Cancer Treatment:
- Edit tumor cells
- Enhance immune cells
3. Agriculture:
- Disease-resistant crops
- Improved nutrition
4. Infectious Disease:
- Edit HIV resistance
- Treatment of genetic infections
Advantages:
- More precise than previous methods
- Less expensive
- Faster editing
- Works in various organisms
Concerns:
- Off-target effects
- Ethical issues
- Germline modification ethics
Q (2021, 3 marks): Explain the concept of Polymerase Chain Reaction (PCR) and its applications.
Answer: Polymerase Chain Reaction (PCR):
Definition - Technique to amplify specific DNA sequences.
Process (Cycles repeat 25-35 times):
1. Denaturation (94-95 degrees C):
- DNA double helix separates
- Forms single strands
2. Annealing (50-65 degrees C):
- Primers attach to target sequence
- Primers are short complementary sequences
3. Extension (72 degrees C):
- DNA polymerase synthesizes new DNA
- Extends from primer
- Creates new DNA strands
Result:
- Exponential amplification
- Doubles DNA with each cycle
- Original 1 copy becomes 2^n copies
Applications:
1. Diagnostics:
- Detection of viral infections
- COVID-19 testing
- Bacterial identification
2. Forensics:
- DNA fingerprinting from crime scenes
- Paternity testing
- Individual identification
3. Research:
- Gene expression studies
- Mutation detection
4. Cloning:
- Amplification of genes for cloning
5. Evolutionary Studies:
- Ancient DNA analysis
- Species identification
Frequently Asked Questions
What is the difference between traditional and modern biotechnology?
Traditional biotechnology uses natural biological processes (fermentation, composting) for product creation, while modern biotechnology involves direct manipulation of genes through techniques like genetic engineering and CRISPR.
Is genetically modified food safe to eat?
Scientific consensus indicates that properly tested and approved genetically modified foods are safe for consumption, though ongoing research and regulation ensure safety standards.
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