Deoxyribonucleic acid (DNA), although it does not have a particularly attractive name, is the key element for all existing life and the evolution of species . It is a molecule that contains and encodes the specific genetic information of each species and that, we could say, contains the biological instructions that are passed from a subject to their descendants. In the case of humans, for example, the human genome consists of 3 billion bases organized in 23 pairs of chromosomes that contain about 20,000 genes .
The two chains that form it are composed of nucleotides (an organic molecule made up of deoxyribose, a phosphate and a nitrogenous base) that join through weak hydrogen bonds and form a double helix structure . Except in certain phases of cell division in which the DNA chains unwind, these structures are found within the nucleus of cells packed into chromosomes or in mitochondria.
The first time that there is evidence of an observation of DNA was at the end of the 19th century, by the Swiss biochemist Frederich Miescher . But for years, scientists and experts around the world debated the role of DNA, a molecule they considered too simple to contain biological information , and it was not until 1953 that the importance of this was made known. James Watson and Francis Crick, building on previous work by Rosalind Franklin, deciphered the double helix structure of DNA through X-ray diffraction .
Since then, DNA and genetic research have become major players in scientific advances: from the definitive sequencing of the human genome to cloning projects, artificial protein synthesis or genetic editing and correction methods. The possibilities and new horizons that seem to open up are overwhelming and every day more and more applications and possibilities derived from the study of DNA are known . But, as it is difficult to imagine all those microscopic chains within us, we offer you a selection of portraits of all kinds to learn more about DNA.
