🧬 Biotechnology: Principles and Processes
| Category | NCERT Examples | Key High-Yield Feature / Application |
|---|---|---|
| First Recombinant DNA | Constructed by Stanley Cohen and Herbert Boyer (1972) | Linked an antibiotic resistance gene with a native plasmid of Salmonella typhimurium. |
| First Restriction Endonuclease | HindII | Always cuts DNA molecules at a specific sequence of 6 base pairs. |
| Enzyme Nomenclature | EcoRI from Escherichia coli RY 13 | • E: Genus (Escherichia) • co: Species (coli) • R: Strain • I: Order of isolation. |
| Palindromic Sequence | EcoRI cutting site | Reads 5'—GAATTC—3' and 3'—CTTAAG—5'; cuts between G and A. |
| Sticky End Producers | EcoRI, HindIII, BamHI | Leave single-stranded overhanging stretches at the ends. |
| Blunt End Producers | SmaI, EcoRV | Cut straight across both strands (less frequently tested but a key contrast). |
| Cell Wall Digesting Enzymes | • Lysozyme (Bacteria) • Chitinase (Fungi) • Cellulase (Plant cells) | Used to isolate pure DNA by breaking outer protective layers. |
| Cloning Vector (Artificial) | pBR322 | Contains selectable markers: Amplicillin (\(amp^{R}\)) and Tetracycline (\(tet^{R}\)) resistance genes. |
| Natural Plant Vector | Agrobacterium tumefaciens | Delivers T-DNA via its Ti-plasmid to transform normal plant cells into tumor cells. |
| Natural Animal Vector | Retroviruses | Disarmed to deliver desirable genes into animal host cells. |
| Direct Gene Transfer Methods | • Micro-injection: Animal cells • Biolistics / Gene Gun: Plant cells | • Micro-injection targets the nucleus directly. • Biolistics uses gold/tungsten particles coated with DNA. |
| Polymerase Chain Reaction (PCR) | Taq polymerase | Thermostable DNA polymerase isolated from the bacterium Thermus aquaticus. |
🌾 Biotechnology and its Applications
| Category / Product | NCERT Source / Organism | High-Yield Medical / Agricultural Feature |
|---|---|---|
| Bt Cotton | Bacillus thuringiensis | Contains cry genes (e.g., cryIAc, cryIIAb control cotton bollworms; cryIAb controls corn borer). |
| RNA Interference (RNAi) | Meloidogyne incognita | Nematode that infects tobacco plant roots; silenced using double-stranded RNA (dsRNA). |
| Genetically Engineered Insulin | Humulin (Eli Lilly company, 1983) | Prepared by introducing DNA sequences for chains A and B separately into E. coli plasmids. |
| First Gene Therapy (1990) | 4-year-old girl with ADA deficiency | Caused by the deletion of the gene for Adenosine Deaminase; treated using lymphocytes. |
| Transgenic Cow | Rosie (1997) | Produced human protein-enriched milk containing human alpha-lactalbumin (2.4 grams per litre). |
| Transgenic Fish / Animals | Transgenic mice, pigs, sheep, cows, and fish | 95% of all existing transgenic animals are mice (primarily used for vaccine safety testing). |
| Biopiracy Landmark Case | Basmati Rice patent (1997) | An American company got patent rights on Basmati rice through the US Patent and Trademark Office. |