Biotechnology is the use of living organisms in engineering, medicine, and technology. It involves genetic engineering and tissue culture. Biotechnology can be used to easily and cheaply manufacture existing medicines and make production of substances like human growth hormone and insulin easier. It is also used to genetically engineer microorganisms like E. coli and yeast to produce substances. Biotechnology applications include transgenic plants and animals. It can also be applied to environmental modification and protection by using microorganisms to degrade pollutants and promote sustainable development with low environmental impact. Biotechnology is important for examinations in areas like short notes, essays, and its applications to environmental protection.