NCERT
Every NCERT book that matters for UPSC — open a book, then a chapter. Learn each chapter's concepts, then how UPSC tests them — with diagrams, flowcharts and the past questions to attempt.
0% read
← Biology — all chaptersBiotechnology and its Applications
Start here: why this chapter matters
In simple wordsChapter 9 was the workshop — scissors, glue, delivery vans, photocopier and factory tank. This chapter is the showroom: a cotton plant that poisons only the caterpillar eating it, a tobacco root that starves its worm, a bacterium that makes human insulin, a child whose own blood cells were given a missing gene, tests that spot a virus before you feel ill, and mice built to stand in for human patients. It ends with the hard questions — who decides what is safe, and who owns living things.
This is the tenth chapter of NCERT's Class 12 Biology textbook (pages 177–187 of the 2026-27 reprint), the second and last chapter of Unit IX, Biotechnology. It has four parts — applications in agriculture (10.1: tissue culture, GM crops, Bt cotton, RNAi), applications in medicine (10.2: insulin, gene therapy, molecular diagnosis), transgenic animals (10.3) and ethical issues (10.4: GEAC, patents, biopiracy) — with Figures 10.1–10.3, a summary and 13 exercises. This page uses nine concept sections.
- Neighbouring chapters: Biotechnology: Principles and Processes (Chapter 9) supplies every tool used here — restriction enzymes, vectors, the Agrobacterium Ti plasmid, disarmed retroviruses, PCR, bioreactors. Microbes in Human Welfare (Chapter 8) introduced Bt sprays and Bt cotton; Human Health and Disease (Chapter 7) explains the immune system that ADA deficiency cripples and the ELISA test for HIV; Molecular Basis of Inheritance (Chapter 5) gives mRNA, translation and the probes of DNA fingerprinting; Sexual Reproduction in Flowering Plants (Chapter 1) covers hybrid seed and GM mustard's male sterility.
- Prelims — science and technology, environment: Bt genes from a bacterium (1999, 2000, 2001), Bt brinjal (2011, 2012), Bollgard (2021), Mon 863 maize (2010), GM mustard (2018), golden rice (2010), RNAi (2019), gene silencing in transgenic crops (2014), genetic medicine (2026), insulin as a peptide (2004), ELISA (1987), tissue culture (1985), genetic engineering's effects (1990), GEAC's ministry and parent Act (2003, 2015), the National Biodiversity Authority and biopiracy (2012).
- GS3 — Science and Technology, agriculture, IPR: biotechnology and biopharma (2018), biotechnology for farmers (2019), applied biotechnology for the poor (2021), biotechnology for perishable crops (2026); traditional knowledge, TKDL and patents (2015, 2019), IPR in life materials (2024). GS2 touches it through health policy and regulation; GS4 through the ethics of gene therapy and patents on life.
| Word | What it means here |
|---|---|
| Explant | any part of a plant taken out and grown in a test tube under sterile conditions |
| Totipotency | the capacity of a cell or explant to give rise to a whole plant |
| Somaclones | plants produced by micropropagation — genetically identical to the parent |
| Protoplast | a plant cell whose wall has been digested away, leaving the plasma membrane |
| GMO | a plant, bacterium, fungus or animal whose genes have been altered by manipulation |
| Protoxin | an inactive form of a toxin that must be activated (here by the insect's alkaline gut) |
| RNA interference (RNAi) | silencing of a specific mRNA by a complementary double-stranded RNA |
| Recombinant therapeutic | a medicine made by recombinant DNA technology, e.g. human insulin |
| Gene therapy | inserting genes into a person's cells and tissues to treat a disease |
| ELISA | enzyme-linked immunosorbent assay — detects antigens or antibodies by antigen–antibody binding |
| Transgenic animal | an animal whose DNA has been manipulated to possess and express an extra (foreign) gene |
| Biopiracy | use of bio-resources by companies or organisations without proper authorisation and compensatory payment |
Reading NCERT's chapter opening (page 177)The opening page shows a QR code and a small tilted photograph of a hand holding two cotton bolls — one blackened and damaged, one bursting white (the same image as Figure 10.1) — beside the list of four sections and an introduction: biotechnology is industrial-scale production of biopharmaceuticals and biologicals using GM microbes, fungi, plants and animals; its applications include therapeutics, diagnostics, GM crops, processed food, bioremediation, waste treatment and energy production; and its three critical research areas are the best catalyst, optimal conditions and downstream processing. The point: the chapter's emblem is Bt cotton, and its frame is food and health.
At a glance — the six ideas to carry away
- Three research areas: best catalyst (improved organism or pure enzyme), optimal conditions, downstream processing. Three options for food: agro-chemical, organic, GM crop-based. Green Revolution tripled food supply but not enough; agrochemicals costly.
- Tissue culture (1950s): whole plants from explants = totipotency; medium of sucrose, salts, vitamins, amino acids, auxins, cytokinins. Micropropagation → genetically identical somaclones (tomato, banana, apple). Meristem is virus-free → virus-free banana, sugarcane, potato. Protoplast fusion → somatic hybrid (pomato — not commercial).
- GMOs: genes altered by manipulation. GM crops: stress tolerance, less pesticide, fewer post-harvest losses, efficient mineral use, nutrition (golden rice, vitamin A). Bt toxin from Bacillus thuringiensis kills lepidopterans, coleopterans, dipterans; stored as inactive protoxin crystals, activated by alkaline gut pH, makes pores in midgut cells. Genes: cryIAc, cryIIAb (cotton bollworms), cryIAb (corn borer).
- RNAi: dsRNA silences a matching mRNA — a natural eukaryotic defence. Meloidogyne incognita on tobacco roots: Agrobacterium puts in a nematode gene giving sense + antisense RNA → dsRNA → nematode cannot survive.
- Medicine: about 30 recombinant therapeutics worldwide, 12 marketed in India. Insulin = chains A and B joined by disulphide bridges; made as proinsulin with a C peptide. Eli Lilly, 1983: A and B chains made separately in E. coli, combined. Gene therapy: first in 1990, 4-year-old girl, ADA deficiency; lymphocytes + ADA cDNA via retroviral vector; periodic infusion. Diagnosis: rDNA, PCR (HIV, cancer mutations), radioactive probe + autoradiography, ELISA (antigen–antibody).
- Transgenic animals (>95% mice): physiology (insulin-like growth factor), disease models (cancer, cystic fibrosis, rheumatoid arthritis, Alzheimer's), products (α-1-antitrypsin for emphysema; Rosie the cow, 1997, 2.4 g/L human α-lactalbumin), vaccine safety (polio), toxicity testing. Ethics: GEAC; patents; biopiracy — basmati (US patent 1997; 27 documented varieties; ~200,000 rice varieties in India), turmeric, neem; Indian Patents Bill second amendment.
1. Agriculture without genes moved: tissue culture
In simple wordsEvery plant cell carries the full instruction book for the whole plant. Give a tiny piece the right food and hormones in a clean bottle, and it can rebuild the entire plant — again and again, so one good banana plant becomes ten thousand identical ones. And because viruses rarely reach the growing tip, starting from that tip gives clean, virus-free plants.
To raise food production there are three options: agro-chemical-based agriculture, organic agriculture, and genetically engineered crop-based agriculture. The Green Revolution tripled the food supply, yet not enough for the growing population; its gains came partly from improved varieties but mainly from better management and agrochemicals (fertilisers and pesticides), which are often too expensive for farmers in the developing world, and further gains with existing varieties are not possible by conventional breeding.
As breeding failed to keep pace, tissue culture developed. In the 1950s scientists learnt that whole plants could be regenerated from explants — any part of a plant taken out and grown in a test tube under sterile conditions on special nutrient media. This capacity to generate a whole plant from any cell or explant is totipotency. The medium must provide a carbon source such as sucrose, inorganic salts, vitamins, amino acids and growth regulators such as auxins and cytokinins. Large numbers of plants can then be raised in a very short time — micropropagation. Each is genetically identical to the original: they are somaclones. Tomato, banana, apple and other food plants have been produced commercially this way.
Virus-free plants. Even in a virus-infected plant the meristem (apical and axillary) is free of virus, so it can be removed and grown in vitro to get virus-free plants; meristems of banana, sugarcane and potato have been cultured. Somatic hybridisation. Single cells are isolated and their walls digested to give naked protoplasts (surrounded by the plasma membrane). Protoplasts from two different varieties, each with a desirable character, can be fused into a hybrid protoplast and grown into a new plant — a somatic hybrid. Tomato and potato protoplasts were fused to make the pomato, which unfortunately did not combine the desired characteristics for commercial use.
⤵ Micropropagation
Choosea mother plant of the desired variety; take an explant (for virus-free plants, the meristem)
Sterilise and plantplace it on a sterile medium: sucrose, inorganic salts, vitamins, amino acids, auxins and cytokinins
Callus and shootscells divide; growth regulators steer shoot and then root formation
Multiplypieces are subcultured to give thousands of plantlets in a short time
Harden and plant outthe somaclones, genetically identical to the parent, go to the field
Common confusions
- Tissue culture is not genetic engineering: micropropagation copies an existing genotype; no gene is moved.
- Somaclones are genetically identical to the parent (NCERT's sense); ‘somaclonal variation’, the occasional differences that arise in culture, is a Beyond NCERT idea.
- Virus-free plants come from the meristem, not from leaves or roots (exercise 1).
- Somatic hybrids fuse protoplasts (body cells), not gametes; they can cross species barriers that sexual crosses cannot.
- The pomato was made but was not commercially useful.
- UPSC 1985 asked ‘what is tissue culture?’ — it is growing cells, tissues or organs in a sterile nutrient medium outside the organism.
Beyond NCERT
- Gottlieb Haberlandt proposed in 1902 that plant cells are totipotent.
- Tissue-cultured banana plantlets are widely used in India; certification of tissue-culture labs is done under the Department of Biotechnology's National Certification System for Tissue Culture Raised Plants.
2. Genetically modified crops
In simple wordsBreeding mixes two whole recipe books and hopes the good recipes end up together. Genetic modification copies one recipe — say, for a pest-killing protein or for vitamin A — from any living thing into a crop. That precision is the promise; whether the changed crop is safe for people, fields and farmers is the argument.
Genetically Modified Organisms (GMOs) are plants, bacteria, fungi and animals whose genes have been altered by manipulation. Genetic modification of plants has: (i) made crops more tolerant to abiotic stresses (cold, drought, salt, heat); (ii) reduced reliance on chemical pesticides (pest-resistant crops); (iii) helped reduce post-harvest losses; (iv) increased efficiency of mineral use (preventing early exhaustion of soil fertility); and (v) enhanced nutritional value, e.g. golden rice, vitamin-A-enriched rice. GM has also made tailor-made plants supplying industry with alternative resources — starches, fuels and pharmaceuticals.
Bt toxin is made by the bacterium Bacillus thuringiensis (Bt). Its gene has been cloned and expressed in plants to give resistance to insects without insecticides — in effect a bio-pesticide. Examples: Bt cotton, Bt corn, rice, tomato, potato and soyabean.
| Position on GM crops (attributed) | What it emphasises |
|---|---|
| NCERT | GM crops raise yields, cut pesticide use and post-harvest losses, and improve nutrition; GM organisms can have unpredictable effects in ecosystems, so they need regulation (GEAC) |
| India's regulator (Genetic Engineering Appraisal Committee, environment ministry) | case-by-case biosafety appraisal: approved Bt cotton for commercial cultivation in 2002; Bt brinjal was placed under a moratorium by the environment ministry in February 2010; GM mustard DMH-11 was cleared for environmental release in 2022, a clearance challenged in the Supreme Court |
| Supporters (many crop scientists, seed industry, some farmer organisations) | less spraying, higher and more stable yields, nutrition gains such as golden rice, tools against drought and pests that breeding alone cannot give |
| Critics (some farmer groups, environmental and consumer organisations, some scientists) | pests evolving resistance, seed cost and dependence on companies, gene flow to wild relatives, effects on biodiversity and non-target organisms, health concerns, preference for organic or agro-ecological methods |
The table records positions, not a verdict. NCERT exercise 6 asks for exactly this comparison; its outline below follows the same balance.
Common confusions
- Golden rice carries pro-vitamin A (β-carotene), which the body converts to vitamin A (UPSC 2010) — not extra yield, essential amino acids or vitamin D.
- Bt is a bacterium, not a fungus (UPSC 1999, 2000, 2001; 2012's ‘soil fungus’ statement is wrong).
- Bt brinjal's purpose is pest resistance (UPSC 2011). The public objections were about health and biodiversity; Bt seeds are not terminator seeds (UPSC 2012).
- Bollgard I and II are GM (Bt) cotton technologies (UPSC 2021), not clonal propagation.
- Mon 863 is a GM pest-resistant maize (UPSC 2010).
- GM mustard DMH-11 uses genes for male sterility and fertility restoration to make hybrids (UPSC 2018) — it is not a pest-resistant crop and was developed at the University of Delhi, not IARI–PAU.
- NCERT calls GEAC the Genetic Engineering ‘Approval’ Committee; its name became ‘Appraisal’ Committee in 2010. UPSC 2003 used the old name; UPSC 2015 the new one.
Beyond NCERT
- Golden rice was engineered with genes for the β-carotene pathway (originally from daffodil and a soil bacterium; later versions use a maize gene).
- Pink bollworm has evolved resistance to Bt cotton in parts of India — an example of natural selection (Chapter 6).
- GEAC functions under the Environment (Protection) Act, 1986, through the Rules of 1989 (UPSC 2015), and sits in the environment ministry (UPSC 2003).
3. Bt cotton: a crop that makes its own insecticide
In simple wordsThe Bt bacterium keeps its weapon in a locked box — a crystal of harmless protein. The lock opens only in the gut of certain insect larvae, which is strongly alkaline. So the poison does nothing to the bacterium, the plant, or to us (our stomachs are acidic), but it punches holes in the gut of the caterpillar that bites the cotton boll.
Some strains of Bacillus thuringiensis make proteins that kill certain insects: lepidopterans (tobacco budworm, armyworm), coleopterans (beetles) and dipterans (flies, mosquitoes). During a particular phase of growth the bacterium forms protein crystals containing a toxic insecticidal protein. Why does the toxin not kill the Bacillus? It exists as an inactive protoxin. When an insect ingests it, the alkaline pH of the gut solubilises the crystals and converts it into the active toxin, which binds to the surface of midgut epithelial cells and creates pores that cause cell swelling and lysis and eventually the death of the insect.
Specific Bt toxin genes were isolated and put into crops such as cotton. The choice of genes depends on the crop and the target pest, since most Bt toxins are insect-group specific. The toxin is coded by a gene named cry; there are many. The proteins encoded by cryIAc and cryIIAb control cotton bollworms; that of cryIAb controls the corn borer.
Reading NCERT's Figure 10.1 (page 180)A photograph of a hand holding a cotton stem with three bolls against a dark background: (a) two bolls blackened, shrivelled and holed — destroyed by bollworms; (b) a fully mature boll bursting with clean white lint. The point: bollworms destroy the boll itself, the part farmers sell — which is why cotton was the first Bt crop in India.
⤵ From protoxin to a dead larva
Stored safelyBacillus thuringiensis (or the Bt plant) holds the toxin as an inactive protoxin crystal
Eatenan insect larva, e.g. a bollworm, eats the leaf or boll
Activatedthe alkaline pH of the larval gut dissolves the crystal and converts the protoxin to active toxin
Bindsactive toxin binds the surface of midgut epithelial cells
Killspores form; the cells swell and lyse; the insect dies
| Gene (NCERT's name) | Standard name (Beyond NCERT) | Pest controlled |
|---|---|---|
| cryIAc | cry1Ac | cotton bollworms |
| cryIIAb | cry2Ab | cotton bollworms |
| cryIAb | cry1Ab | corn borer |
Common confusions — Bt toxin vs Bt gene
- The Bt gene (cry) is the DNA moved into the crop; the Bt toxin (Cry protein) is what the plant then makes. The gene name is italic lower-case (cry); the protein is ‘Cry’.
- The toxin is inactive inside the bacterium (exercise 4: answer c, ‘toxin is inactive’) — not because the bacterium is resistant or keeps it in a sac.
- Activation needs alkaline gut pH — not acidic.
- Most Bt toxins are insect-group specific: bollworm toxins differ from corn-borer toxins.
- A Bt spray (Chapter 8) is the bacterium's spores applied from outside; a Bt crop makes the toxin in its own cells.
- NCERT's sentence ‘coded by a gene cryIAc named cry’ is garbled; read it as ‘the toxin is coded by genes named cry, e.g. cryIAc’.
Beyond NCERT
- India's first Bt cotton hybrids (approved 2002) carried cry1Ac (‘Bollgard I’); ‘Bollgard II’ added cry2Ab, two toxins making resistance slower to evolve.
- Farmers are asked to plant a refuge of non-Bt cotton so susceptible insects survive and dilute resistance.
4. RNA interference: silencing a pest's gene
In simple wordsA gene works by sending out a message (mRNA) that the cell reads to make a protein. RNAi is a shredder for one particular message: give the cell a double-stranded copy of that message and the cell silences every matching copy. If the plant makes a double-stranded copy of a vital worm message, the worm that sucks the plant's juice swallows its own silencer.
Several nematodes parasitise plants and animals, humans included. The nematode Meloidogyne incognita infects the roots of tobacco and greatly reduces yield. A novel strategy used RNA interference (RNAi), which takes place in all eukaryotes as a method of cellular defence: a specific mRNA is silenced by a complementary dsRNA molecule that binds to it and prevents its translation. Naturally, the complementary RNA may come from infection by viruses with RNA genomes, or from mobile genetic elements (transposons) that replicate through an RNA intermediate.
Using Agrobacterium vectors, nematode-specific genes were introduced into the host plant so that they produced both sense and antisense RNA in the host cells. Being complementary, the two RNAs formed dsRNA, which initiated RNAi and silenced the specific mRNA of the nematode. The parasite could not survive in a transgenic host expressing the specific interfering RNA, so the plant was protected.
Reading NCERT's Figure 10.2 (page 181)Two photographs of tobacco roots: (a) roots of a typical control plant, crowded with swollen knots and galls (arrows; an inset enlarges one gall); (b) transgenic plant roots five days after deliberate infection with the nematode — long, clean and fibrous, with only a few faint marks. The point: the dsRNA made by the host plant protects the roots from the infestation that knots the control.
⤵ Making a nematode-resistant plant by RNAi
Pick the targetan essential gene of Meloidogyne incognita
Build the constructarrange it so the plant makes both sense and antisense RNA of that gene
Transferuse an Agrobacterium vector to put the construct into tobacco
dsRNA formsthe complementary sense and antisense RNAs pair into double-stranded RNA
Silencingwhen the nematode feeds, the dsRNA silences its matching mRNA; the parasite cannot survive
Common confusions
- RNAi stops translation of a specific mRNA — it does not delete or mutate the gene.
- The silencer is double-stranded RNA, made from sense + antisense RNA, not a protein.
- The genes put into tobacco were nematode genes, not Bt genes; the vector was Agrobacterium.
- RNAi occurs naturally in all eukaryotes; its natural sources are RNA viruses and RNA-copying transposons.
- UPSC 2014: gene silencing is a technique for transgenic crops; budding and grafting are not. UPSC 2019: RNAi is used for gene-silencing therapies, possible cancer therapies and virus-resistant crops, not hormone replacement.
- NCERT prints ‘Meloidegyne incognitia’; the correct spelling is Meloidogyne incognita (root-knot nematode).
Beyond NCERT
- Andrew Fire and Craig Mello shared the 2006 Nobel Prize in Physiology or Medicine for discovering RNA interference.
- Inside cells, an enzyme (Dicer) chops dsRNA into short pieces that guide a protein complex (RISC) to the matching mRNA.
- RNAi-based medicines (‘siRNA drugs’) have been approved for some rare diseases.
5. Medicine: recombinant therapeutics and human insulin
In simple wordsFor decades diabetics injected insulin taken from the pancreas of slaughtered cows and pigs — close to ours but not the same, so some patients reacted to it. Recombinant DNA turned bacteria into tiny insulin factories making the exact human molecule. The trick was assembly: the body makes insulin as one long chain and then snips out a middle piece; bacteria cannot do that, so the two final pieces were made separately and joined.
Recombinant DNA technology has enabled mass production of safe and more effective therapeutic drugs, which do not induce the unwanted immune responses common with similar products from non-human sources. About 30 recombinant therapeutics have been approved for human use worldwide; 12 are marketed in India (NCERT's figures).
Insulin. Adult-onset diabetes can be managed by taking insulin at regular intervals. Insulin was earlier extracted from the pancreas of slaughtered cattle and pigs; as a foreign protein it caused allergy or other reactions in some patients. Insulin consists of two short polypeptide chains, A and B, linked by disulphide bridges. In mammals it is synthesised as a pro-hormone (proinsulin) containing an extra stretch, the C peptide, which is removed during maturation. Getting insulin assembled into its mature form was the main challenge. In 1983 Eli Lilly, an American company, prepared two DNA sequences for the A and B chains of human insulin and introduced them into plasmids of E. coli; the chains were produced separately, extracted and combined by creating disulphide bonds to form human insulin.
Reading NCERT's Figure 10.3 (page 182)‘Maturation of pro-insulin into insulin (simplified)’: a grey loop labelled ‘Proinsulin’ joins a blue strand and a green strand marked with S–S links; an arrow leads to a separate blue ‘A peptide’ and green ‘B peptide’ held by S–S bonds as ‘Insulin’, plus a grey ‘Free C peptide’. The point: insulin's two chains come from one precursor whose middle piece is cut out — the step bacteria cannot do, hence Eli Lilly's separate-chain route.
⤵ Human insulin from E. coli (Eli Lilly, 1983)
Two DNAsprepare DNA sequences coding for the A chain and the B chain of human insulin
Into plasmidsinsert each into plasmids and transfer them into E. coli
Expressthe bacteria make chain A and chain B separately
Extractpurify the two chains
Combinejoin them by creating disulphide bonds: human insulin, identical to the natural molecule
Common confusions
- Insulin is a peptide (protein) hormone (UPSC 2004) of two chains, A and B, joined by disulphide bridges — not peptide bonds between the chains.
- The C peptide is in proinsulin only; mature insulin lacks it.
- Eli Lilly made the chains separately in E. coli and joined them outside the cell.
- Insulin cannot be taken orally: as a protein it would be digested by gut proteases (NCERT's in-text question).
- NCERT says ‘adult-onset diabetes’ is managed by insulin. Many adult-onset (type 2) patients are treated first with diet and tablets; insulin is essential in type 1 diabetes. Write ‘insulin-dependent diabetes’ to be safe.
Beyond NCERT
- The A chain has 21 and the B chain 30 amino acids — 51 in all — with two disulphide bridges between the chains and one within the A chain.
- Eli Lilly's recombinant human insulin, made with technology from Genentech, was first approved in the United States in 1982 and marketed from 1983; use NCERT's 1983.
- Other recombinant therapeutics: human growth hormone, erythropoietin, tissue plasminogen activator, interferons, clotting factor VIII, the hepatitis B vaccine.
Why this matters for GS3Mains 2018 asked why India's biotechnology sector is so active and how it has helped biopharma. The biology here is the base: recombinant therapeutics are identical to human proteins, safer than animal-derived ones, and made at scale in bioreactors (Chapter 9). Add India's strengths as pointers — vaccines, biosimilars (copies of off-patent biologics such as insulin), contract manufacturing, a skilled workforce, and the Department of Biotechnology's support — and the regulatory need for clinical trials and quality control.
6. Gene therapy: the ADA story
In simple wordsIf a child is born missing one instruction in the body's manual, gene therapy tries to paste in a correct copy. In the first attempt, doctors took some of a girl's white blood cells, used a tamed virus to give them the missing instruction, and put them back. It helped — but blood cells don't live forever, so the treatment had to be repeated.
Gene therapy is a collection of methods that allows correction of a gene defect diagnosed in a child or embryo: genes are inserted into a person's cells and tissues to treat a disease. A normal gene is delivered into the individual or embryo to take over the function of, and compensate for, the non-functional gene.
The first clinical gene therapy was given in 1990 to a 4-year-old girl with adenosine deaminase (ADA) deficiency. ADA is crucial for the immune system; the disorder is caused by deletion of the ADA gene. Some children are cured by bone-marrow transplantation; others are treated by enzyme replacement therapy (functional ADA given by injection) — but neither is completely curative. In gene therapy, lymphocytes from the patient's blood are grown in culture outside the body; a functional ADA cDNA is introduced into them using a retroviral vector; and they are returned to the patient. As these cells are not immortal, the patient needs periodic infusions. If the gene, isolated from marrow cells producing ADA, were introduced into cells at early embryonic stages, it could be a permanent cure.
⤵ Gene therapy for ADA deficiency
Collecttake lymphocytes from the patient's blood
Culturegrow them outside the body
Deliver the geneintroduce a functional ADA cDNA with a disarmed retroviral vector
Returninfuse the engineered lymphocytes back into the patient
Repeatthe cells are not immortal, so infusions are repeated periodically
| Position on gene therapy (attributed) | What it emphasises |
|---|---|
| NCERT | gene therapy can correct hereditary defects; introducing the gene at early embryonic stages could be a permanent cure |
| Clinicians and researchers developing somatic gene therapy | treats the patient alone; can cure or control diseases with no other remedy; delivery tools are improving |
| Cautious scientists and bioethicists | risks such as immune reactions and a vector inserting at a harmful place; high cost and unequal access; germline or embryo changes would pass to future generations who cannot consent |
| Many national laws and guidelines, including India's | permit regulated somatic gene therapy trials; germline genetic modification of human embryos for pregnancy is not permitted |
The table records positions, not a verdict.
Common confusions
- The 1990 therapy was somatic and ex vivo (cells treated outside the body) — not a permanent cure; NCERT's ‘permanent cure’ needs early embryonic cells.
- The vector was a retrovirus (disarmed), carrying ADA cDNA.
- Enzyme replacement gives the protein; gene therapy gives the gene.
- ADA deficiency is an immune disorder (severe combined immunodeficiency), not a blood-sugar or blood-clotting disorder.
- UPSC 2026: genetic medicines correct or compensate for faulty genes and use engineered viruses or lipid nanoparticles as carriers; they do not alter the entire DNA sequence.
- NCERT's Summary says gene therapy may involve ‘gene targeting which involves gene amplification’ — loosely worded; the core idea is replacing or compensating for a defective allele.
Beyond NCERT
- ADA deficiency causes a form of severe combined immunodeficiency (SCID). The 1990 trial was run at the US National Institutes of Health.
- Newer gene therapies use adeno-associated viruses or lipid nanoparticles as carriers; CRISPR–Cas9 (Chapter 9) allows editing a gene in place.
7. Molecular diagnosis: catching disease early
In simple wordsOrdinary tests wait until there is enough germ to cause symptoms — like noticing a fire only when you see flames. Molecular tests detect the smoke: PCR copies a pathogen's few DNA molecules a billion times until they can be seen; a probe sticks only to an exact matching sequence; ELISA uses antibodies that grab one specific protein and makes it change colour.
Early diagnosis and understanding the disease are vital, but conventional methods (serum and urine analysis) cannot detect disease early. Recombinant DNA technology, PCR and ELISA serve early diagnosis. A pathogen is normally suspected only after it has caused symptoms, by which time its concentration is already very high. A very low concentration of a bacterium or virus, before symptoms, can be detected by amplifying its nucleic acid by PCR. PCR is now routinely used to detect HIV in suspected AIDS patients, to detect mutations in genes in suspected cancer patients, and to identify many other genetic disorders.
Probes. A single-stranded DNA or RNA tagged with a radioactive molecule — a probe — is allowed to hybridise to its complementary DNA in a clone of cells, and detected by autoradiography. A clone with the mutated gene will not appear on the photographic film, because the probe is not complementary to it. ELISA is based on antigen–antibody interaction: infection is detected by the presence of antigens (proteins, glycoproteins, etc.) or of antibodies made against the pathogen.
| Method | Detects | Principle | Example in NCERT |
|---|---|---|---|
| PCR | a pathogen's nucleic acid or a mutation | amplifies a few DNA copies until detectable | HIV in suspected AIDS; gene mutations in suspected cancer |
| Probe + autoradiography | a specific sequence (normal vs mutated gene) | complementary base pairing of a radioactive probe | a mutated gene gives no signal |
| ELISA | antigens or antibodies | antigen–antibody binding, read by an enzyme reaction | infection by a pathogen (e.g. HIV, Chapter 7) |
Common confusions
- PCR detects nucleic acid; ELISA detects proteins (antigens) or antibodies.
- In the probe test the mutated clone gives no spot, because the probe cannot pair with it.
- ELISA = Enzyme-Linked Immunosorbent Assay; the ‘enzyme’ makes the colour, not the antibody.
- UPSC 1987 keyed ELISA for AIDS — still the standard screening test.
- PCR is sensitive because copies double each cycle: 10 starting copies become over 10 billion after 30 ideal cycles (asserted in the source file).
Beyond NCERT
- RT-PCR first makes DNA from viral RNA (HIV, SARS-CoV-2) and then amplifies it; ‘viral load’ tests count copies.
- Fluorescent tags have largely replaced radioactive probes.
- Rapid antigen tests use the same antibody principle as ELISA on a paper strip.
8. Transgenic animals
In simple wordsTo understand a broken car part, engineers build a car with that part deliberately broken. Biologists do the same with mice: add or change a gene, and watch what happens. Such animals become living models of human diseases, testers of vaccine safety, and — in cows and goats — producers of human proteins in their milk.
Transgenic animals have had their DNA manipulated to possess and express an extra (foreign) gene. Transgenic rats, rabbits, pigs, sheep, cows and fish have been made, but over 95 per cent of all existing transgenic animals are mice. Why make them?
| Use | What it means | NCERT's example |
|---|---|---|
| Normal physiology and development | study how genes are regulated and affect body functions and development | insulin-like growth factor: genes from other species alter its formation, revealing its role |
| Study of disease | models of human diseases for investigating new treatments | cancer, cystic fibrosis, rheumatoid arthritis, Alzheimer's |
| Biological products | animals given a gene for a useful product, cheaper than other methods | human α-1-antitrypsin for emphysema; attempts for phenylketonuria and cystic fibrosis; Rosie, the first transgenic cow (1997): milk with human α-lactalbumin, 2.4 g per litre, nutritionally more balanced for babies |
| Vaccine safety | test vaccine batches before human use | transgenic mice for polio vaccine safety — could replace monkeys |
| Chemical safety (toxicity) testing | animals made more sensitive to toxins give results in less time | same procedure as drug toxicity testing |
⤵ Making and using a transgenic animal (outline)
Choose the genee.g. a human protein gene, or a disease gene to model
Introduce ite.g. by micro-injection of DNA into the nucleus of a fertilised egg (Chapter 9)
Developthe embryo is implanted and grows into an animal carrying the gene
Check expressionconfirm the animal possesses and expresses the foreign gene
Useresearch model, product (e.g. protein in milk), or safety tester
Common confusions
- A transgenic animal carries a foreign gene; a cloned animal (such as Dolly the sheep, by somatic cell nuclear transfer) is a genetic copy of another — different ideas (Dolly is Beyond NCERT).
- Rosie was a cow (1997) whose milk carried human α-lactalbumin; α-1-antitrypsin is a different protein, for emphysema.
- Over 95% of transgenic animals are mice, not rats.
- Transgenic mice test polio vaccine safety, potentially replacing monkeys.
- UPSC 1993: a giant mouse made with a human growth-hormone gene is a product of genetic engineering (a transgenic mouse).
Beyond NCERT
- Animal ‘pharming’ — making drugs in milk — has produced approved medicines, such as a human anticoagulant protein from transgenic goats.
- Laboratory use of animals in India is regulated under the Prevention of Cruelty to Animals Act, 1960, through a committee that oversees animal experiments.
9. Ethical issues: regulation, patents and biopiracy
In simple wordsSuppose a village has used a herb for a thousand years, and a distant company tweaks it slightly, patents it, and then charges the village to use it. Is that invention or theft? Who should get paid? And who checks that a new GM organism will not upset an ecosystem? These are the questions this last part raises.
The manipulation of living organisms cannot go on without regulation; ethical standards are needed to judge the morality of activities that might help or harm living organisms. Biologically, genetically modified organisms can have unpredictable results when introduced into ecosystems. So the Indian Government set up bodies such as GEAC (NCERT: Genetic Engineering Approval Committee), which decides on the validity of GM research and the safety of introducing GM organisms for public services. The use of living organisms for public services (food, medicine) has also created problems with patents: there is growing public anger that companies are granted patents for products and technologies using genetic materials, plants and other biological resources long identified, developed and used by farmers and indigenous people.
Basmati. Rice goes back thousands of years in Asia; India alone has an estimated 200,000 varieties, one of the richest diversities in the world. Basmati is distinct for its aroma and flavour; 27 documented varieties are grown in India, and it appears in ancient texts, folklore and poetry. In 1997 an American company got patent rights on basmati rice through the US Patent and Trademark Office, letting it sell a ‘new’ variety in the US and abroad — a variety actually derived from Indian farmers' varieties by crossing Indian basmati with semi-dwarf varieties and claimed as an invention. The patent extended to functional equivalents, so other sellers of basmati could be restricted. Attempts have also been made to patent uses, products and processes based on Indian traditional herbal medicines, such as turmeric and neem.
Biopiracy is the use of bio-resources by multinational companies and other organisations without proper authorisation from the countries and people concerned and without compensatory payment. Industrialised nations are rich financially but poor in biodiversity and traditional knowledge; developing and underdeveloped nations are the reverse. Traditional knowledge can be used to develop modern applications and save time, effort and money in commercialisation. With growing realisation of injustice and inadequate compensation and benefit sharing, some nations are making laws against unauthorised exploitation; NCERT notes that Parliament ‘recently’ cleared the second amendment of the Indian Patents Bill, which takes such issues into account, including emergency provisions and research and development initiatives.
Reading NCERT's basmati and biopiracy passage (page 185)There is no figure; the page is a short case study. Its facts — about 200,000 rice varieties in India, 27 documented basmati varieties, a US patent of 1997 extending to ‘functional equivalents’ — lead to a definition of biopiracy and the contrast between financially rich, biodiversity-poor nations and biodiversity-rich developing ones. The point: traditional knowledge has economic value, and protecting it needs law and vigilance.
| Case (Beyond NCERT details) | What happened | How it ended |
|---|---|---|
| Turmeric | a US patent (1995) on using turmeric to heal wounds | revoked in 1997 after India's Council of Scientific and Industrial Research showed prior traditional use, including old texts |
| Neem | a European patent on a neem-based fungicide | revoked by the European Patent Office in 2000 for lack of novelty; upheld on appeal in 2005 |
| Basmati | a US patent (1997) on basmati lines and grains | after India's challenge, most of the claims were withdrawn or narrowed (2001) |
| Position on patents and bio-resources (attributed) | What it emphasises |
|---|---|
| NCERT and the Government of India | patents on long-used biological resources and traditional knowledge are biopiracy; vigilance, opposition to such patents and laws on benefit sharing are needed |
| Patent holders and much of the biotechnology industry | patents reward the investment and risk of research; a genuinely new, useful variety or process deserves protection |
| International agreements (Convention on Biological Diversity, 1992; Nagoya Protocol, 2010) | countries have sovereign rights over their genetic resources; access needs prior informed consent and benefits should be shared fairly |
| Farmers' and indigenous groups | communities who developed the resources should be recognised and rewarded; seeds and knowledge are held in common |
The tables record positions and outcomes, not a verdict.
⤵ How India responds to a biopiracy patent
Spot ita patent application or grant abroad claims a use or product based on Indian bio-resources or traditional knowledge
Gather prior artcollect documented evidence of earlier traditional use (texts, records, databases)
Challengefile opposition or re-examination before the foreign patent office
Outcomethe patent is revoked or its claims narrowed (turmeric, neem, basmati)
Preventdomestic laws on access and benefit sharing, and patent-office access to traditional-knowledge databases
Common confusions
- Biopiracy = use without authorisation and without compensation; legal use with consent and benefit sharing is bioprospecting (Beyond NCERT term).
- The basmati patent was granted by the US Patent and Trademark Office in 1997 to an American company; the ‘new’ basmati came from crossing Indian basmati with semi-dwarf varieties.
- India has about 200,000 rice varieties; 27 documented basmati varieties.
- GEAC sits in the environment ministry (UPSC 2003), constituted under the Environment (Protection) Act, 1986 (UPSC 2015) — not under the Food Safety Act or the GI Act.
- The National Biodiversity Authority checks biopiracy, and an IPR application involving Indian biological resources needs its approval; it does not supervise GM crop research (UPSC 2012).
- NCERT's ‘recently cleared’ second amendment of the Patents Bill is dated text; it became the Patents (Amendment) Act, 2002.
Beyond NCERT
- India's Biological Diversity Act, 2002 created the National Biodiversity Authority (Chennai) to regulate access to biological resources and benefit sharing.
- The Traditional Knowledge Digital Library (TKDL), built by CSIR and the AYUSH ministry, translates traditional formulations into a searchable form that patent examiners can use as prior art (Mains 2015, 2019).
- Section 3(d) and related clauses of India's Patents Act limit patents on mere new forms of known substances and on plants, animals and essentially biological processes; plant varieties are protected instead under the Protection of Plant Varieties and Farmers' Rights Act, 2001.
- ‘Basmati’ also has Geographical Indication protection in India.
Why this matters for GS3Mains has asked how India protects traditional medicine knowledge from patenting (2019), about TKDL's role against erroneous patents (2015) and about IPR in life materials (2024). Frame: the problem (NCERT's biopiracy: basmati, turmeric, neem) → India's tools (opposing foreign patents with documented prior art, TKDL, the Biological Diversity Act and NBA approval, patent-law limits, plant-variety and GI protection) → international rules (CBD, Nagoya Protocol, TRIPS) → limits and debates, presented as attributed positions.
NCERT's in-text questions — short answers
The chapter asks eight questions in its running text and suggests one visit.
Page 178: What does tissue culture mean?
Growing plant cells, tissues or organs (explants) in a test tube under sterile conditions on a nutrient medium, so that whole plants can be regenerated — possible because plant cells are totipotent.
Page 179: Is there an alternative path that genetics can show to get maximum yield while minimising fertilisers and chemicals?
Genetically modified crops: pest-resistant crops (Bt) cut pesticide use, more efficient mineral use cuts fertiliser need, and stress-tolerant crops yield under drought or salinity — with biosafety regulation.
Page 179: Why does this (Bt) toxin not kill the Bacillus?
It is stored as an inactive protoxin crystal; it becomes active only in the alkaline gut of the insect.
Page 181: What would a diabetic patient do if enough human insulin was not available?
Use insulin isolated from other animals (cattle and pig pancreas), as was done earlier — or, today, recombinant human insulin made by bacteria.
Page 181: Would insulin from other animals be just as effective, and would it not elicit an immune response?
It works, because animal insulins are very similar, but they are foreign proteins: some patients developed allergy or other reactions. Recombinant human insulin is identical to ours and avoids this.
Page 181: Can insulin be orally administered to diabetic people? Why?
No (in ordinary form). Insulin is a protein: gut proteases such as pepsin and trypsin would digest it, and a large molecule is poorly absorbed. So it is injected.
Page 183: Can you explain how PCR can detect very low amounts of DNA?
Each PCR cycle doubles the target sequence, so a few copies become millions to billions in about 30 cycles (2³⁰ ≈ 10⁹ per starting copy) — enough to see on a gel or by a fluorescent signal, long before symptoms.
Page 183: Why are these (transgenic) animals being produced? How can man benefit?
To study normal physiology and development, to model human diseases and test treatments, to produce biological products (e.g. α-1-antitrypsin; Rosie's α-lactalbumin milk), to test vaccine safety (polio) and to test chemical toxicity faster.
Activity (page 178): visit a tissue culture laboratory.
Note the laminar-flow hood and autoclave (sterility), the media bottles (sucrose, salts, vitamins, amino acids, hormones), the growth room with lights and temperature control, the stages from explant to callus to shoots to rooted plantlets, and the hardening area.
NCERT exercise — answer outlines
Reading NCERT's Summary and Exercises (pages 186–187)The boxed Summary recaps tissue culture and somatic hybridisation; GMOs made by recombinant DNA; GM plants raising yields, cutting post-harvest losses and pesticide use, adding nutrition; recombinant therapeutics that are identical to human proteins, free of unwanted immune responses and infection risks; human insulin made in bacteria yet identical to the natural molecule; transgenic animals as disease models; gene therapy using virus vectors; and serious ethical questions. Thirteen exercises follow, several asking the student to use the internet.
1. Which part of the plant is best suited for making virus-free plants and why?
The meristem (apical or axillary). Even in an infected plant the meristem is free of virus (its cells divide fast and it lacks connections through which viruses spread), so cultured meristems give virus-free plants — e.g. banana, sugarcane, potato.
2. What is the major advantage of producing plants by micropropagation?
A large number of genetically identical plants (somaclones) of a desired variety in a short time and small space, independent of season; also disease-free (virus-free) planting material.
3. Find out what the various components of the medium used for propagation of an explant in vitro are.
A carbon source (sucrose), inorganic salts (macro- and micronutrients), vitamins, amino acids and growth regulators — auxins and cytokinins (their ratio steers roots vs shoots); usually solidified with agar (Beyond NCERT).
4. Crystals of Bt toxin produced by some bacteria do not kill the bacteria themselves because — (a) bacteria are resistant to the toxin (b) toxin is immature (c) toxin is inactive (d) bacteria encloses toxin in a special sac.
(c) toxin is inactive — it is an inactive protoxin, activated only by the alkaline pH of the insect gut.
5. What are transgenic bacteria? Illustrate using any one example.
Bacteria carrying and expressing a foreign gene introduced by recombinant DNA technology. Example: E. coli carrying plasmids with DNA for the A and B chains of human insulin (Eli Lilly, 1983); the chains are extracted and joined by disulphide bonds into human insulin.
6. Compare and contrast the advantages and disadvantages of production of genetically modified crops.
Advantages cited (NCERT and supporters): tolerance to cold, drought, salt and heat; less chemical pesticide (Bt crops); fewer post-harvest losses; efficient mineral use; better nutrition (golden rice); tailor-made plants for starch, fuel and drugs. Disadvantages cited (NCERT's caution and critics): unpredictable effects in ecosystems; pests evolving resistance; gene flow to wild relatives; possible effects on non-target organisms and biodiversity; health concerns and allergy testing; seed cost and dependence on companies; patent and biopiracy issues. Regulation (GEAC) decides case by case. Present both, without a verdict.
7. What are Cry proteins? Name an organism that produces it. How has man exploited this protein to his benefit?
Cry proteins are insecticidal crystal proteins (Bt toxins) coded by cry genes, made by Bacillus thuringiensis. They are inactive protoxins activated in the alkaline insect gut, where they make pores in midgut cells. Man has used them as bio-pesticide sprays and by putting cry genes into crops — Bt cotton (cryIAc, cryIIAb against bollworms), Bt corn (cryIAb against corn borer) — cutting insecticide use.
8. What is gene therapy? Illustrate using the example of adenosine deaminase (ADA) deficiency.
Insertion of a normal gene into a person's cells or tissues to compensate for a defective one. ADA deficiency (deleted ADA gene; immune failure): in 1990 a 4-year-old girl's lymphocytes were cultured outside the body, given a functional ADA cDNA by a retroviral vector, and returned; as lymphocytes are not immortal, infusions are periodic. A gene introduced at early embryonic stages could be a permanent cure. Alternatives — bone-marrow transplantation, enzyme replacement — are not fully curative.
9. Diagrammatically represent the experimental steps in cloning and expressing a human gene (say the gene for growth hormone) into a bacterium like E. coli.
Steps (draw as boxes with arrows): mRNA for growth hormone from pituitary cells → cDNA by reverse transcriptase (bacteria cannot remove introns) → PCR amplification → cut cDNA and a plasmid (e.g. pBR322 or an expression vector with a bacterial promoter) with the same restriction enzyme → DNA ligase → recombinant plasmid → transform competent E. coli (Ca²⁺, heat shock) → select on antibiotic / blue-white → grow in a bioreactor → express the hormone → downstream processing (separate, purify, formulate, test). Chapter 9's diagrams supply each step.
10. Can you suggest a method to remove oil (hydrocarbon) from seeds based on your understanding of rDNA technology and chemistry of oil?
Oil in seeds is mainly triglycerides (fatty acids + glycerol) made by specific enzymes. Using rDNA technology one could silence the genes of the oil-making pathway in the seed (by RNAi or antisense RNA), so the seed stores starch or protein instead; or express a lipase in the seed to break the oil down. (An open-ended question; any reasoned, gene-based answer is acceptable.)
11. Find out from internet what is golden rice.
A GM rice whose grains make β-carotene (pro-vitamin A), giving them a golden colour; the body converts β-carotene to vitamin A. It aims to reduce vitamin A deficiency (night blindness, weak immunity) where rice is the staple. Its use is debated: supporters cite nutrition, critics prefer diet diversity and supplements and raise biosafety concerns.
12. Does our blood have proteases and nucleases?
Yes. Blood plasma contains proteases — e.g. thrombin and plasmin in clotting and clot breakdown, and complement proteases — and nucleases (such as DNase) that break down free DNA and RNA. This is one reason injected DNA or protein drugs are degraded and must be protected.
13. Consult internet and find out how to make orally active protein pharmaceutical. What is the major problem to be encountered?
The major problem: digestion by stomach acid and gut proteases, and poor absorption of large protein molecules across the gut wall. Approaches: protective coatings or capsules that release the drug in the intestine, protease inhibitors, absorption enhancers, nanoparticle carriers, or redesigned smaller, more stable molecules.
What to remember
Numbers
Chapter pages177–187 (Unit IX's second and last chapter)
Tissue culture discovered1950s
Recombinant therapeutics approvedabout 30 worldwide; 12 marketed in India
Human insulin by Eli Lilly1983 — A and B chains made separately in E. coli
Insulin chains (Beyond NCERT)A 21 + B 30 = 51 amino acids; 3 disulphide bridges
First clinical gene therapy1990 — a 4-year-old girl with ADA deficiency
Transgenic animals that are miceover 95%
Rosie, first transgenic cow1997 — 2.4 g/L human α-lactalbumin in milk
Rice varieties in Indiaabout 200,000
Documented basmati varieties27
Basmati patent (US)1997
Bt cotton approved in India (Beyond NCERT)2002
Bt toxin target groups3 — lepidopterans, coleopterans, dipterans
GM crop benefits listed by NCERT5
Uses of transgenic animals listed5
One-liners
- Totipotency lets a single plant cell or explant grow into a whole plant.
- Micropropagation produces genetically identical somaclones.
- Meristem culture gives virus-free plants.
- Fusing protoplasts gives somatic hybrids such as the pomato.
- Golden rice is enriched with pro-vitamin A.
- Bt toxin is stored as an inactive protoxin.
- The alkaline gut of the insect activates Bt toxin.
- Active Bt toxin makes pores in midgut epithelial cells.
- cryIAc and cryIIAb proteins control cotton bollworms.
- cryIAb protein controls the corn borer.
- RNAi silences a specific mRNA with complementary dsRNA.
- Meloidogyne incognita attacks tobacco roots.
- Sense and antisense RNA pair to form dsRNA.
- Insulin has chains A and B linked by disulphide bridges.
- Proinsulin contains a C peptide removed during maturation.
- Eli Lilly made human insulin in E. coli in 1983.
- The first gene therapy, in 1990, treated ADA deficiency.
- PCR detects pathogens before symptoms appear.
- ELISA works on antigen–antibody interaction.
- Over 95% of transgenic animals are mice.
- Rosie the cow produced human alpha-lactalbumin.
- Biopiracy is use of bio-resources without authorisation or compensation.
Traps to avoid
- Tissue culture copies plants; it does not move genes.
- Somatic hybrids fuse body-cell protoplasts, not gametes.
- Bt is a bacterium, not a fungus.
- Bt toxin is activated by alkaline, not acidic, gut pH.
- The cry gene is the DNA; the Cry protein is the toxin.
- RNAi blocks translation; it does not delete the gene.
- The C peptide is in proinsulin, not in mature insulin.
- Insulin chains are joined by disulphide bridges.
- Insulin cannot be taken orally because gut proteases digest it.
- The 1990 ADA gene therapy was not a permanent cure.
- In the probe test the mutated gene gives no signal.
- A transgenic animal is not the same as a cloned animal.
- GEAC is in the environment ministry, under the Environment (Protection) Act, 1986.
- NCERT's 'Approval' Committee is now the 'Appraisal' Committee.
How to strategise
Prelims — what UPSC asks
- GM crops: Bt genes come from a bacterium (1999, 2000, 2001); Bt brinjal is for pest resistance (2011) and was opposed on health and biodiversity grounds (2012); Bollgard I and II are GM cotton technologies (2021); Mon 863 is pest-resistant GM maize (2010); golden rice carries pro-vitamin A (2010); GM mustard uses genes for hybridisation (2018); gene silencing creates transgenic crops (2014); RNAi uses (2019).
- Medicine and techniques: insulin is a peptide (2004); ELISA is the test for AIDS (1987); genetic medicines correct faulty genes using viruses or lipid nanoparticles as carriers (2026); effects of genetic engineering (1990); tissue culture (1985). Regulation and biopiracy: GEAC under the environment ministry (2003) and constituted under the Environment (Protection) Act, 1986 (2015); the National Biodiversity Authority and biopiracy (2012).
- Key notes: 1985 keyed (a) ‘preparation of fragments of the cells of organism for biochemical examination’ — disputed: strictly, that describes cell fractionation (tissue culture is growing cells or tissues in a nutrient medium), so (d) ‘none of the above’ is arguable; (a) is the intended answer in old keys — pick (a) if it reappears in this form. 1990 lists ‘Closing’ (a misprint for cloning) and keys (c) disease resistance, growth promotion, longevity — a flawed, dated question; NCERT supports disease resistance and growth, not longevity. 2014 keys (b), counting cytoplasmic male sterility as a transgenic technique — disputed: CMS is a natural cytoplasmic trait used in hybrid breeding, though engineered male sterility (as in GM mustard) is transgenic. 2003 uses GEAC's old name ‘Approval’; the key (Environment and Forests) stands.
- Likely next: Cry protein activation, Bt toxin target groups, RNAi and its sources, the C peptide, Eli Lilly's two-chain method, ADA and SCID, probes vs ELISA vs PCR, Rosie and α-lactalbumin, α-1-antitrypsin, transgenic mice for polio vaccine testing, biopiracy cases, the Biological Diversity Act, TKDL, GEAC's status.
Mains — where it appears and how to answer
- GS3 2018 (biotechnology and biopharma), 2019 (biotechnology for farmers), 2021 (applied biotechnology for the poor) and 2026 (biotechnology for perishable crops): use this chapter's list — tissue-culture and virus-free planting material, Bt and RNAi pest resistance, stress-tolerant and nutrient-rich crops, fewer post-harvest losses, recombinant medicines and vaccines, cheap early diagnostics — then add regulation and attributed positions on GM crops. Keep examples precise (Bt cotton 2002, insulin, ADA gene therapy).
- GS3 2015 (TKDL), 2019 (protecting traditional medicine from patents) and 2024 (IPR in life materials): start from NCERT's biopiracy (basmati, turmeric, neem), then India's tools — prior-art challenges, TKDL, the Biological Diversity Act and NBA, patent-law limits, plant-variety and GI protection — and the CBD and Nagoya framework; set out patent-holder and community views side by side.
Self-check
Tap an option. NCERT's own exercise questions come first; the rest test the figures and common confusions.
1. Bt toxin does not kill Bacillus thuringiensis itself because:
2. Which gene's protein controls the corn borer, according to NCERT?
3. In the RNAi strategy against Meloidogyne incognita, the transgenic tobacco produces:
4. Eli Lilly's 1983 method for human insulin involved:
5. The first clinical gene therapy (1990) was for:
6. ELISA detects infection by:
7. Rosie, the first transgenic cow (1997), produced milk containing:
8. Biopiracy, as NCERT defines it, is:
UPSC questions from this chapter
Open any question to attempt it in the Question bank — your attempt is saved to your progress.