DNAmakes us who we are. It is like a tiny “instruction manual” deepin each of our cells that tells our body how to build itself. It alsodetermines what we will be like in looks and personality. Somescientists even believe that our DNA decides how long we will liveand what will make us sick. Although most people’s DNA is similar,there are small differences. Those differences make us individual.

     ADNA strand looks like a pair of coiled strings and is called a“helix”. Each string holds information in the form of chemicals.These chemicals make up a complicated map of our bodies and who weare. Sometimes there can be a problem with a few of the chemicalswhen DNA copies itself, and a “mutation” occurs. Mutations areoften responsible for serious diseases and other problems.

    Scientistshave only recently been able to map out the entire DNA helix. Thiswill allow them to find ways to repair problems in people’s DNA.They say that if they cab change a person’s DNA, they can keep themhealthy for longer, help them live longer and even change the waythey look.