Biology Class 12

 c 11 What is biotechnology? ● Biotechnology refers to the technology using biology, which has applications in agriculture, food processing industry, medicine diagnostics, bioremediation, waste treatment, and energy production. ● The European Federation of Biotechnology (EFB) defines biotechnology as “the integration of natural science and organisms, cells, parts thereof and molecular analogues for products and services”. Basis of Modern Biotechnology ● Genetic engineering − Introduction of foreign genetic material (DNA/RNA) into the host’s genome and altering its phenotype ● Aseptic techniques − Involves maintenance of contamination-free ambience in chemical engineering processes for manufacture of products such as antibiotics, vaccines, etc.This is done so as to enable the growth of only desired microbes responsible for a bioprocess. Genetic Engineering ● Asexual reproduction preserves the genetic information while sexual reproduction preserves variations. ● Plant and animal hy...

 c 12 Genetically Engineered Crops ● Genetically engineered crops have desirable genes (as of insect/pest resistance, giving better yield) incorporated in them. ● Genetically modified crops have ○ more tolerance to abiotic stresses such as cold, drought, salinity, heat, etc. ○ insect/pest resistance ○ reduced post-harvest losses ○ efficient mineral usage by plants ○ enhanced nutritional value (e.g., Vitamin A rich rice) Bt Cotton ● Bacillus thuringiensis is a bacterium that produces proteins to kill certain insects such as lepidopterans (armyworm), coleopterans (beetles), and dipterans (flies/ mosquitoes). B. thuringiensis produces a protein crystal containing a toxic protein (inactivated state). ● Inactivated toxin Activated in the presence of Alkaline PH activated toxin (gut of insect) ● Activated toxin binds to the epithelial cells in the midgut of insect and creates pores that cause lyses and swelling and eventually death of insect. ● This toxin is encoded by a gene called Cry ...