Genes are segments of DNA or RNA which are transmitted through generations, and contain genetic information useful for building the sequence of amino acids to make a protein. Genes are found in the chromosomes, located in the nucleus of the cell.
Another way to define a gene is as a segment of DNA which codes for a polypeptide (and thus a protein).
Protein synthesis Edit
The information is copied from the DNA to the mRNA (messenger RNA) with the help of some enzymes. This messenger then goes outside the nucleus and goes to the ribosome. There, the protein is built along with tRNA (Transfer RNA) and rRNA (ribosomal RNA). The protein is finally built by the rRNA, which assembles each amino acid until the full protein is complete.
Medicine application Edit
There have been many claims of discoveries of new genes; for example: genes that control obesity, esquizophrenia and even the likelihood of committing crimes. Nevertheless, many of these findings have proved to be false. Some authors, like Stephen J. Gould, have argued that this is a reductionist way to treat genetics. He, along with many other scientists, considers a gene to be only a small part of a complicated process in which not only genes and DNA, but enzymes, the environment, and many more factors, intervene. Thus, he recommends to take these new "discoveries" of genes with care.