Genetic engineering, also referred to as recombinant DNA technology, has revolutionized biology by enabling direct manipulation of an organism’s genome. One of its most significant applications is in medicine. The production of therapeutic proteins such as insulin, growth hormones, clotting factors, and monoclonal antibodies has become more efficient and cost-effective through genetically modified microorganisms. Insulin, for example, is now produced by inserting the human insulin gene into *Escherichia coli*, eliminating dependence on animal sources. Gene therapy represents another medical application, where defective genes in patients are replaced or repaired to treat genetic disorders such as cystic fibrosis, hemophilia, and muscular dystrophy. Genetic engineering also plays a role in vaccine development; recombinant vaccines, such as those for hepatitis B and HPV, are produced without using the pathogen itself, increasing safety and effectiveness. In agriculture, genetic engineering has been widely used to create genetically modified (GM) crops with enhanced traits. Crops are engineered for