1. What is a gene?

Every plant and animal is made of cells, each of which has a nucleus. Inside every nucleus there are strings of DNA, organised into structures called chromosomes. If all the DNA in the human body were unravelled it would reach the moon and back 8000 times! Each cell normally holds a double set of chromosomes, one of which is inherited from the mother and one from the father. One set of chromosomes from each parent combines when the sperm fertilises the egg (in the case of animals) or pollen fertilises the ovum (in the case of plants). The cell formed after fertilisation divides into two identical copies, each of which inherits this unique new combination of chromosomes. These embryonic cells then continue to divide again and again. The inherited genetic material, carried in the chromosomes, is therefore identical in each new cell.

DNA is often described as a blueprint which contains all the essential information needed for the structure and function of an organism, and genes are described as the individual messages which make up the blueprint, each gene coding for a particular characteristic. Although this concept can be helpful as a tool for understanding, it runs the risk of reducing the organism to a machine, and viewing physiology as little different from a series of industrial processes.(1) In reality, however, genes are very difficult to define and can only be understood within their context - a living organism.

No gene works in isolation. Genes are sequences of DNA which operate in complex networks that are tightly regulated to enable processes to happen in the right place and at the right time. This intricate network is informed and influenced by environmental feedback in relationships that have been evolving over millions of years. According to Barbara McClintock, who won the Nobel Prize in 1983 for her pioneering work in the field of genetics, the functioning of genes is 'totally dependent on the environment in which they find themselves'. (2)
 

References:

1. Kollek R. The gene - that obscure object of desire. From the book "The Life Industry"
2. Fox Keller E. (1986) Love, power and learning (Liebe, Macht und Erkenntis). Hanser: Munich, p.179.
 

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