Biotechnology uses biology to solve problems and make useful products. Recombinant DNA technology involves combining DNA from different organisms to create new genetic combinations. The key steps are: (1) isolating the gene of interest, (2) cutting the gene and vector with restriction enzymes, (3) inserting the gene into the vector, (4) transforming host cells with the modified vector, and (5) expressing the gene to produce the desired product. Biotechnology has applications in medicine, agriculture, and industry by allowing the large-scale production of drugs, genetically modified crops, and industrial chemicals.