Biotechnology

Chapter Overview

Genetic engineering, also known as recombinant DNA technology, involves isolating a desired gene and inserting it into a host organism using molecular tools. Restriction endonucleases act as molecular scissors to cut DNA at specific palindromic sequences, creating sticky or blunt ends. Plasmids (such as pBR322) act as molecular vectors to carry the foreign gene into host cells, where the recombinant plasmid replicates and expresses the target protein.

A prominent application is the production of human insulin in bacteria. This process involves isolating the insulin genes (for A and B chains), selecting plasmids, creating recombinant DNA, inserting the plasmids into E. coli, producing and purifying the individual polypeptide chains, and folding them with disulfide bridges. The Polymerase Chain Reaction (PCR) is another critical tool, allowing rapid amplification of specific DNA segments through cycles of denaturation, annealing, and extension.

The chapter also covers Genetically Modified Organisms (GMOs), describing transgenic bacteria, pest-resistant plants, and fast-growing transgenic animals. Furthermore, it addresses modern agricultural advancements, explaining the working of soil-free vertical food farms (using hydroponics or aeroponics) and comparing their land, water, and yield efficiency with traditional agricultural practices in Pakistan. Grasping these biotechnology concepts is essential for HSSC-II SLO-based assessments.