Genetic Technology and Biotechnology

The molecular understanding of genes has given rise to powerful technologies for reading, copying, and altering DNA. These tools underpin modern medicine, agriculture, and forensic science, but they also raise ethical questions that societies are still working through. This lesson surveys the core techniques and their applications.

The Polymerase Chain Reaction (PCR)

PCR amplifies a specific segment of DNA, producing millions of copies from a tiny starting sample. It relies on repeated cycles of three temperature-controlled steps:

• Denaturation (around $95^\circ\text{C}$): heat separates the double helix into single strands.
• Annealing (around $55^\circ\text{C}$): short DNA primers bind to the ends of the target sequence.
• Extension (around $72^\circ\text{C}$): a heat-stable enzyme, Taq poly