ABSTRACT
Modern biotechnology has been made possible by breakthroughs in the understanding of how living organisms function at the sub-cellular level, and in particular by increasing knowledge of the structure and function of DNA. DNAis present in every cell in our bodies, as well as almost every other living
organism. Its two key features are its ability to replicate itself and so transmit heritable characteristics down the generations, and its control of the production of proteins. Proteins play a very central role in a living organism: they form its structure (for example, in muscles and tissues) and control the biochemical processes which are carried on in the body (enzymes and antibodies, for example, are proteins). Through the study of DNA and genes, scientists have been able to understand how different proteins are produced and what particular genes are involved in their production. Scientists have also developed an understanding of how variations in the DNA of an organism (called polymorphisms) produce different characteristics (or phenotypes) in the organism itself. Some of these characteristics might be beneficial, for example, producing disease resistance or increased growth; others may be detrimental, for example, a variation in the BRCA1 or BRCA2 genes in human beings leads to an increased risk of breast and ovarian cancer. Through the use of biotechnological techniques, it is possible for scientists to alter the DNA sequence of an organism and to ‘cut and paste’ DNA from one organism into another, both of which can create desired characteristics or eradicate unwanted characteristics in the organism: this process is commonly referred to as ‘genetic engineering’.
