Answer:
Medicinal: In the medical world, the concepts of genetic engineering are being widely used to combat various diseases. The techniques in biotechnology have helped in producing various proteins which are beneficial to humans. For example, insulin and vaccines are being made through recombinant DNA technology.
Agricultural: The use of genetic engineering for the production of improved crops is one of the best applications of this technology. Now, it is possible to protect plants from pests and other diseases just by recombinant DNA technology. Also, the formation of crops with improved nutrients like golden rice has enabled to fight malnutrition.
Environmental: The techniques in genetic engineering has now made it possible to provide better ways for bio remediation. Toxic waste management has been made possible by producing bacteria that can even degrade plastics along with other waste.