Summary
NCERT Class 12 Biology Chapter 10, Biotechnology and Its Applications, covers how biotechnology is used in agriculture (GM crops, Bt toxin, RNAi-based pest resistance), medicine (recombinant insulin, gene therapy, molecular diagnosis), and transgenic animals, along with the ethical issues surrounding genetic modification and biopiracy.
Chapter 10 explores the practical applications of biotechnology across three major domains. In agriculture, it covers tissue culture (micropropagation, somatic hybridisation), genetically modified organisms (GMOs) such as Bt cotton that use the Bacillus thuringiensis cry gene to resist pests, and RNAi-based strategies to protect plants from nematodes. In medicine, it discusses recombinant human insulin (first produced by Eli Lilly in 1983 using E. coli), gene therapy (first applied in 1990 for ADA deficiency), and molecular diagnostic tools like PCR and ELISA. Transgenic animals are used to study disease, produce biological products, and test vaccine and chemical safety. The chapter concludes with ethical concerns including biopiracy and India's GEAC regulatory body.
Key points & formulas
- 01Bt toxin from Bacillus thuringiensis is expressed in GM crops (Bt cotton, Bt corn) via cry genes (e.g., cryIAc, cryIIAb) to confer insect resistance without chemical pesticides.
- 02RNAi (RNA interference) is used to protect tobacco plants from the nematode Meloidegyne incognita by introducing nematode-specific dsRNA via Agrobacterium vectors.
- 03Recombinant human insulin was first produced in 1983 by Eli Lilly by separately expressing insulin chain A and chain B in E. coli plasmids and then combining them with disulfide bonds.
- 04The first clinical gene therapy was administered in 1990 to a 4-year-old girl with ADA (adenosine deaminase) deficiency, using retroviral vectors to introduce functional ADA cDNA into her lymphocytes.
- 05PCR and ELISA are key molecular diagnostic tools; PCR detects very low concentrations of pathogens (e.g., HIV) and mutations in cancer-suspected genes before symptoms appear.
- 06GEAC (Genetic Engineering Approval Committee) is India's regulatory body for GM research; biopiracy — unauthorised use of bio-resources by multinationals without compensation — is a major ethical concern addressed by Indian patent law amendments.
Frequently asked questions
01What is Bt toxin and how does it work in Bt cotton?
Bt toxin is an insecticidal protein produced by Bacillus thuringiensis in crystal form. In insects, the alkaline gut pH solubilises the inactive protoxin into its active form, which binds to midgut epithelial cells, creates pores, causes cell swelling and lysis, and kills the insect. In Bt cotton, the cry genes (cryIAc and cryIIAb) from B. thuringiensis are incorporated into the plant genome to control cotton bollworms without chemical pesticides.
02What was the significance of the first gene therapy case mentioned in Chapter 10?
In 1990, gene therapy was first clinically applied to a 4-year-old girl suffering from ADA deficiency, a condition caused by deletion of the gene for adenosine deaminase, which is essential for immune system function. Functional ADA cDNA was introduced into her lymphocytes using a retroviral vector, and these cells were reinfused into her body. While not a permanent cure (requiring periodic infusions), it demonstrated the feasibility of gene therapy.
03How is recombinant human insulin different from animal-sourced insulin?
Animal-sourced insulin (from cattle or pigs) caused allergic or immune reactions in some patients because it is a foreign protein. Recombinant human insulin, produced by introducing separate A-chain and B-chain DNA sequences into E. coli plasmids (first achieved by Eli Lilly in 1983), has a structure identical to natural human insulin and therefore does not induce unwanted immunological responses.
04Is the NCERT Class 12 Biology Chapter 10 PDF free to download?
Yes, the NCERT Class 12 Biology Chapter 10 PDF is free to download on cbseprepmaster.com.
More chapters in Biology
This is the complete Biology Chapter 10 as published by NCERT — every diagram, solved example, and exercise included, free. Browse all CBSE Class 12 textbooks.
Read offline with notes, solutions & mock tests
CBSE Prepmaster — free on iOS & Android