Biotechnology and Applications

🟢 Lite — Quick Review (1h–1d)

Rapid summary for last-minute revision before your exam.

Biotechnology — Key Facts for Sri Lanka A/L Examination

Definition: Use of living organisms, cells, or biological systems to develop products and technologies

Traditional vs Modern Biotechnology:

Traditional	Modern
Fermentation	Genetic engineering
Selective breeding	Gene cloning
Hybridization	DNA technology
Tissue culture	Stem cell technology

Key Techniques:

Technique	Description
Genetic Engineering	Direct DNA manipulation
Recombinant DNA	Combining DNA from different sources
PCR	Amplifying specific DNA sequences
Gene cloning	Making copies of genes

⚡ A/L Exam Tip: Gene therapy is the treatment of genetic diseases by inserting functional genes - but it’s not yet widely available for most conditions!

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🟡 Standard — Regular Study (2d–2mo)

Standard content for students with a few days to months.

Biotechnology — Detailed Study Guide

Genetic Engineering

Key Steps in Genetic Engineering:

1. Isolation: Isolate the gene of interest
2. Cutting: Use restriction enzymes to cut DNA
3. Vector construction: Insert gene into plasmid/vector
4. Transformation: Introduce vector into host cell
5. Selection: Select transformed cells
6. Expression: Verify gene is expressed

Restriction Enzymes:

Enzyme	Source	Recognition Site
EcoRI	E. coli	GAATTC
HindIII	H. influenzae	AAGCTT
BamHI	B. amyloliquifaciens	GGATCC

Vectors:

Vector	Size	Host	Special Features
Plasmid	Small	Bacteria	Easy to manipulate
Bacteriophage	Medium	Bacteria	Efficient transfer
Cosmid	Large	Bacteria	Carry large fragments
YAC	Very large	Yeast	Chromosome-like
Ti plasmid	Large	Plants	Plant transformation

Gene Cloning

Process:

1. Isolate gene from donor organism
2. Cut gene with restriction enzyme
3. Insert into plasmid vector
4. Transform into bacterial cell
5. Plate on antibiotic medium (selection)
6. Colony screening (verify insertion)
7. Large-scale culture for protein production

Applications of Cloned Genes:

Product	Application
Insulin	Diabetes treatment
Human growth hormone	Growth disorders
Interferon	Antiviral therapy
Erythropoietin	Anemia treatment
Vaccines	Disease prevention

DNA Analysis Techniques

PCR (Polymerase Chain Reaction):

Component	Function
Template DNA	DNA to be amplified
Primers	Short sequences flanking target
DNA polymerase	Synthesizes new DNA
dNTPs	Building blocks for DNA

Applications:

• Forensic identification
• Disease diagnosis
• Genetic testing
• Paternity testing

DNA Sequencing:

• Determining order of nucleotides
• Sanger method (dideoxy chain termination)
• Next-generation sequencing (massively parallel)

DNA Profiling:

• Uses variable number tandem repeats (VNTRs)
• Unique to each individual (except identical twins)
• Applications: Forensic, paternity, evolutionary studies

⚡ A/L PYQ: “What is the role of restriction enzymes in genetic engineering?” Answer: They recognize and cut DNA at specific sequences, allowing precise removal or insertion of genes.

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🔴 Extended — Deep Study (3mo+)

Comprehensive coverage for students on a longer study timeline.

Biotechnology — Complete Notes for A/L Sri Lanka

Plant Tissue Culture

Principle: Totipotency - any plant cell can give rise to a whole plant

Steps:

1. Explant selection (leaf, stem, root)
2. Surface sterilization
3. Inoculation on sterile medium
4. Callus formation (auxin + cytokinin)
5. Shoot regeneration (high cytokinin)
6. Root induction (high auxin)
7. Acclimatization and hardening
8. Transfer to soil

Culture Media:

• Murashige and Skoog (MS) medium - commonly used
• Contains: Macronutrients, micronutrients, vitamins, amino acids, sucrose, growth regulators

Types of Tissue Culture:

Type	Description
Meristem culture	Virus-free plant production
Embryo culture	Rescue of hybrid embryos
Protoplast culture	Fusion of plant cells
Anther culture	Haploid plant production

Applications:

Application	Example
Clonal propagation	Orchids, banana
Virus elimination	Sugarcane, potato
Germplasm storage	Conservation
Secondary metabolites	Medicinal compounds

Sri Lankan Applications:

• Coconut somatic embryogenesis
• Orchid commercial production
• Banana meristem culture
• Tea micropropagation

Fermentation Technology

Types of Fermentation:

Type	Organism	Product
Alcoholic	Yeast	Ethanol, CO₂
Lactic acid	Bacteria	Yogurt, cheese
Acetic acid	Acetobacter	Vinegar
Butanol	Clostridium	Butanol, acetone

Industrial Applications:

Product	Organism	Use
Penicillin	Penicillium chrysogenum	Antibiotic
Streptomycin	Streptomyces	Antibiotic
Citric acid	Aspergillus niger	Food additive
Vitamin B12	Propionibacterium	Nutritional supplement
Single cell protein	Candida	Food supplement

Bioreactors:

• Large-scale culture vessels
• Controlled environment
• Aeration, temperature, pH control
• Fed-batch and continuous culture

Bioinformatics

Definition: Computer-based analysis of biological data

Applications:

Application	Description
Genome sequencing	Analyzing large-scale DNA data
Protein structure prediction	Modeling 3D structures
Drug discovery	Identifying drug targets
Phylogenetic analysis	Evolutionary relationships

Databases:

• GenBank (DNA sequences)
• PDB (Protein structures)
• SwissProt (Protein annotations)

GMO and Ethical Issues

Genetically Modified Organisms (GMOs):

Crop	Modification	Benefit
Bt cotton	Insecticidal gene	Pest resistance
Golden rice	Vitamin A genes	Nutrition
Roundup Ready soy	Herbicide tolerance	Weed control
Flavr Savr tomato	Delayed ripening	Extended shelf life

Bt Cotton in India/Sri Lanka Region:

• Contains gene from Bacillus thuringiensis
• Produces protein toxic to bollworms
• Reduces pesticide use
• Controversial in some regions

Ethical Concerns:

Concern	Issue
Environmental	Gene escape to wild relatives
Health	Allergenicity, unknown effects
Socioeconomic	Corporate control of seeds
Biodiversity	Reduced genetic diversity

Regulation:

• Cartagena Protocol (biosafety)
• Labeling requirements
• Precautionary principle

GCE A/L Sri Lanka Past Paper Tips

Common Structured Questions:

1. “What is meant by genetic engineering? Describe the main steps involved” (10 marks)
2. “Explain the process of plant tissue culture” (12 marks)
3. “Describe the uses of restriction enzymes in DNA technology” (8 marks)
4. “What are the advantages and disadvantages of genetically modified crops?” (12 marks)
5. “Explain the principle of polymerase chain reaction (PCR)” (10 marks)

Diagram Questions:

1. Draw and label a plasmid vector showing selectable markers (6 marks)
2. Draw a flowchart of gene cloning procedure (8 marks)
3. Draw LS of a bioreactor and label its parts (8 marks)

Essay Questions:

1. “Discuss the applications of biotechnology in agriculture, medicine, and industry” (20 marks)
2. “Evaluate the ethical considerations surrounding the use of genetically modified organisms” (15 marks)

Case Studies:

• Bt cotton adoption in India
• Golden Rice and vitamin A deficiency
• Tissue culture in Sri Lankan orchid industry

⚡ A/L Strategy: For biotechnology questions, always relate theory to practical applications. Sri Lanka’s agricultural sector could benefit greatly from biotechnology - knowing local examples (tea, coconut, rice improvements) demonstrates deeper understanding!

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