Genes Genes are DNA (deoxyribonucleic acid) segments found inside every human cell. They're so little that they can only be seen with a strong microscope. DNA is made up of four molecules that combine to form pairs in various configurations. The combinations generate codes for several genes. Each person has approximately 20,000 genes. Different qualities are coded for by the … [Read more...] about Genetic Disorders: How Much Does Genes Matter?