Every living organism acts in a directed way, each moments of its life, this is because the highly stable DNA molecules give instructions and information indicating what to do. For humans, instructions of the genes provide, during embryonic development, the system of reference standards at which to aim, e.g. the cells of the hypothalamus ensure that the right amount of food and drink are taken and the right amount is incorporated to allow the body to grow to its proper size. Throughout life, the genes continue giving instructions to the cells as to how to select the right chemical action to fare the eventualities that are likely to cause the body to disintegrate. The information is embodied in an enormous long string described as genetic code, provided by the sequences of three nucleotide bases. The reference standards in our brains influence our wants and desires, our satisfactions and revulsions, our longings and our fears. The causes of actions of a given man will include not only all the above variables but also his free will.[91]