Concepts of Genetics

Studying the human genome allows us to explore fundamental details about ourselves at the molecular level. The results of the Human Genome Project are expected to shed considerable light on basic questions, such as how many genes we have, how genes direct the activities of living cells, how species evolve, how single cells develop into complex tissues, and how defective genes cause disease. Furthermore, such understanding may lend itself to improvements in modern medicine by providing better diagnoses of diseases and the development of new treatments for them.As scientists have attempted to unravel the mysteries within our genes, this journey has involved the invention of many new technologies. This textbook emphasizes a large number of these modern approaches. For example, new technologies have made it possible to produce medicines that would otherwise be difficult or impossible to make. An example is human recombinant insulin, sold under the brand name Humulin, which is synthesized in strains of Escherichia coli bacteria that have been genetically altered by the addition of genes that encode the functional regions of human insulin. The bacteria are grown in a laboratory and make large amounts of human insulin, which is purified and adminis-tered to millions of people with insulin-dependent diabetes. Chapter 20 describes the production of insulin in greater detail and also examines other ways that genetic approaches have applications in the area of biotechnology.