NCERT Solutions for Class 12 Biology Chapter 10 Biotechnology and its Applications

Short Note:

• Genetically Modified (GM) crops have been developed to improve yield, provide resistance to pests, herbicides, or environmental stress, and enhance nutritional value; for example, Bt cotton and Bt brinjal contain genes from the bacterium Bacillus thuringiensis that produce toxins effective against specific insect pests without harming other organisms.

• RNA interference (RNAi) technology has been used to develop pest-resistant plants, such as tobacco plants resistant to nematodes, by silencing specific genes essential to the pest's survival.

Short Note:

• Recombinant DNA technology has enabled the large-scale, safe production of therapeutic proteins, such as human insulin (produced using genetically engineered E. coli, marketed as Humulin), overcoming earlier issues with insulin extracted from animal sources.

• Gene therapy is an experimental technique used to correct genetic defects by inserting a normal, functional gene into an individual's cells, as demonstrated in the treatment of Adenosine Deaminase (ADA) deficiency, an immune disorder.

• Molecular diagnosis techniques such as PCR and ELISA allow for the early and accurate detection of diseases, including genetic disorders and infections like HIV, often before symptoms even appear.

Short Note:

• Transgenic animals, which have foreign DNA incorporated into their genome, are used in biological research to study gene regulation, disease models, and the production of biological products such as therapeutic proteins in milk.

• Key ethical and biosafety concerns surrounding biotechnology include the long-term environmental impact of GM crops, the need for regulation by bodies like the GEAC (Genetic Engineering Appraisal Committee) in India, and issues of biopiracy, where bioresources and traditional knowledge of a country are exploited or patented by other nations or corporations without fair compensation.