π Topic 01 of 6 Β· Chapter 04 Β· Biotechnology & Genetic Engineering
Biotechnology Basics β DNA, Genes & Techniques
DNA structure, recombinant DNA, PCR, gel electrophoresis, DNA fingerprinting β complete notes for UPSC & PSC exams.
𧬠DNA β Structure & Key Facts
- DNA = Deoxyribonucleic Acid = genetic material of most organisms
- Double helix structure discovered by James Watson and Francis Crick (1953) β Nobel Prize 1962
- DNA is made of nucleotides β each has a sugar (deoxyribose), phosphate group, and nitrogenous base
- 4 bases: Adenine (A), Thymine (T), Guanine (G), Cytosine (C)
- Base pairing: A-T and G-C (complementary base pairing)
- Human genome = ~3 billion base pairs; ~20,000-25,000 genes
- Gene = segment of DNA that codes for a protein
𧬠Key Biotechnology Techniques
| Technique | What it Does | Applications |
|---|---|---|
| Recombinant DNA Technology | Cuts and joins DNA from different organisms using restriction enzymes and ligases | GM crops, insulin production, vaccines, gene therapy |
| PCR (Polymerase Chain Reaction) | Amplifies specific DNA sequences β makes millions of copies | COVID-19 testing, forensics, paternity testing, disease diagnosis |
| Gel Electrophoresis | Separates DNA fragments by size using electric current | DNA fingerprinting, genetic analysis |
| DNA Fingerprinting | Creates unique DNA profile using VNTRs (variable number tandem repeats) | Forensics, paternity testing, identifying disaster victims |
| Cloning | Creates genetically identical copies of organisms or genes | Dolly the sheep (1996) = first cloned mammal |
| Gene Sequencing | Reads the order of nucleotides in DNA | Human Genome Project; personalised medicine |
𧬠Key Discoveries & Nobel Prizes
- DNA double helix β Watson & Crick (1953) β Nobel Prize 1962
- PCR β Kary Mullis (1983) β Nobel Prize Chemistry 1993
- DNA fingerprinting β Alec Jeffreys (1984)
- Restriction enzymes β Werner Arber, Daniel Nathans, Hamilton Smith β Nobel Prize 1978
- Human Genome Project β completed 2003 β sequenced entire human genome
π Key Exam Points:
β’ DNA double helix = Watson & Crick (1953) = Nobel Prize 1962
β’ PCR = Kary Mullis (1983) = amplifies DNA = COVID-19 testing
β’ DNA fingerprinting = Alec Jeffreys (1984) = forensics
β’ Human Genome Project = completed 2003 = ~3 billion base pairs
β’ Recombinant DNA = restriction enzymes + ligases = basis of genetic engineering
β’ DNA double helix = Watson & Crick (1953) = Nobel Prize 1962
β’ PCR = Kary Mullis (1983) = amplifies DNA = COVID-19 testing
β’ DNA fingerprinting = Alec Jeffreys (1984) = forensics
β’ Human Genome Project = completed 2003 = ~3 billion base pairs
β’ Recombinant DNA = restriction enzymes + ligases = basis of genetic engineering