# Biotechnology and its Applications Notes | SwaVid Biotechnology and its Applications, NCERT Class 12 Biology: notes with key ideas, key terms, common mistakes and 3 quick checks with worked answers. Canonical: https://www.swavid.com/cbse/class-12/biology/chapter/biotechnology-and-its-applications Source: https://www.swavid.com/cbse/class-12/biology/chapter/biotechnology-and-its-applications # Biotechnology and its Applications ## Key terms ## Key ideas ## Common mistakes ## Quick checks ## Keep going ## Questions parents ask ## Class 12 Biology on SwaVid ### Biotechnological applications in agriculture ### Bt cotton and pest resistance ### RNA interference in plants ### Genetically engineered human insulin ### Gene therapy for ADA deficiency ### Molecular diagnosis ### Transgenic animals and biosafety ### Next chapter ### Related chapter ### Related chapter ### Related chapter ### All chapters SwaVid › CBSE › Class 12 › Biology › Biotechnology and its Applications Notes written by SwaVid from the NCERT textbook. Class 12 Biology, Chapter 10. Key ideas, formulas and common mistakes. CBSE prints 12 marks for Unit IX, not for this chapter alone. Short answer. This chapter explains the practical applications of biotechnology in agriculture, medicine, and industry, alongside biosafety and ethical concerns. Students learn how recombinant DNA technology produces pest-resistant crops, genetically engineered insulin, gene therapies, and transgenic animals. Source: NCERT Biology (Reprint 2026-27) , Chapter 10, Biotechnology and its Applications Genetically modified crops increase food production, enhance tolerance to abiotic stresses, reduce reliance on chemical pesticides, and minimize post-harvest losses. Examples include Bt cotton, which produces insecticidal proteins, and vitamin A-enriched Golden rice. Bacillus thuringiensis forms protein crystals containing inactive protoxins called Cry proteins. When ingested by insects like lepidopterans, coleopterans, and dipterans, the alkaline pH of the insect midgut solubilises the crystals, creating pores that cause cell swelling, lysis, and death. RNA interference (RNAi) takes place in all eukaryotic organisms as a method of cellular defense against mobile genetic elements and viruses. Agrobacterium vectors introduce nematode-specific genes into tobacco plants, producing complementary sense and antisense RNA that form dsRNA to silence target mRNA of the nematode Meloidogyne incognita. Mammalian insulin is synthesized as a pro-hormone with an extra peptide called the C-peptide, which is removed during maturation. In 1983, Eli Lilly prepared two DNA sequences corresponding to chains A and B of human insulin, introduced them into Escherichia coli plasmids, and linked the separated chains with disulfide bonds. Adenosine deaminase (ADA) deficiency causes severe combined immunodeficiency. In 1990, a four-year-old patient received functional ADA cDNA via a retroviral vector into cultured lymphocytes, though bone marrow transplantation or gene transfer at early embryonic stages is needed for a permanent cure. Techniques like Polymerase Chain Reaction (PCR), Recombinant DNA Technology, and Enzyme Linked Immuno-Sorbent Assay (ELISA) enable early pathogen detection before clinical symptoms appear. PCR detects minute amounts of pathogen DNA or mutations, while ELISA detects antigens or antibodies. Animals with manipulated DNA are used to study physiology, model human diseases, test vaccine and chemical safety, and produce biological products like human alpha-1-antitrypsin. The Genetic Engineering Appraisal Committee (GEAC) regulates the validity and safety of introducing genetically modified organisms in India. Try each question first. Then tap it to see the answer. Bt toxin is synthesized and stored as an inactive protoxin within the bacterium. Conversion to the active toxin requires an alkaline pH to solubilise the crystals. The bacterial cytoplasm lacks this alkaline environment, so the toxin remains non-toxic to the host. It exists as an inactive protoxin that requires an alkaline pH to become active. Identify the nematode parasite named in the chapter: Meloidogyne incognita. Recall the cellular defense mechanism triggered using Agrobacterium vectors. The method introduces nematode-specific DNA to produce dsRNA that initiates RNA interference (RNAi). Meloidogyne incognita; prevented by RNA interference (RNAi). Recall the transgenic cow Rosie produced in 1997. Identify the human protein enrichment in her milk. Retrieve the concentration stated in the textbook: 2.4 grams per litre. Human alpha-lactalbumin at a concentration of 2.4 g/L. Organisms and Populations . Biotechnology: Principles and Processes . Molecular Basis of Inheritance . Microbes in Human Welfare . The 13 chapters of Class 12 Biology . CBSE does not give marks to one chapter. It prints 12 marks for Unit IX, Biotechnology and its Applications, which includes Biotechnology and its Applications. No. They are written by SwaVid from the NCERT textbook. The CBSE curriculum is the reference for what is assessed. Organisms and Populations. SwaVid is an AI tutor for Indian students in Classes 6 to 12. It finds the earlier ideas a child missed, then teaches today’s chapter. Start free to see how it works. - Ch 10 NCERT book - 12 marks, Unit IX - 3 quick checks - Believing Bt toxin kills Bacillus thuringiensis inside the bacterial cell . Remember that Bt toxin exists as an inactive protoxin in bacteria and only becomes active in the alkaline pH of the insect midgut. - Confusing the targets of cryIAc, cryIIAb, and cryIAb genes . Always associate cryIAc and cryIIAb with cotton bollworms, and cryIAb with the corn borer. - Thinking mature human insulin contains chains A, B, and C . Remember that C-peptide is present only in pro-insulin and is completely removed during the maturation process of functional insulin. - Assuming periodic infusion of genetically modified lymphocytes permanently cures ADA deficiency . State that lymphocytes are not immortal, making infusions temporary, whereas introducing functional ADA cDNA into bone marrow cells at early embryonic stages is a permanent cure. ## Key Links - [CBSE](https://www.swavid.com/cbse) - [Class 12](https://www.swavid.com/cbse/class-12) - [Biology](https://www.swavid.com/cbse/class-12/biology/chapters) - [Start free →](https://www.swavid.com/signup) - [All 13 chapters](https://www.swavid.com/cbse/class-12/biology/chapters) - [NCERT Biology (Reprint 2026-27)](https://ncert.nic.in/textbook.php) - [Open notes](https://www.swavid.com/cbse/class-12/biology/chapter/organisms-and-populations) - [Open notes](https://www.swavid.com/cbse/class-12/biology/chapter/biotechnology-principles-and-processes) - [Open notes](https://www.swavid.com/cbse/class-12/biology/chapter/molecular-basis-of-inheritance) - [Open notes](https://www.swavid.com/cbse/class-12/biology/chapter/microbes-in-human-welfare) - [Class 12 Biology](https://www.swavid.com/cbse/class-12/biology/chapters) - [Start free →](https://www.swavid.com/signup)