Deoxyribonucleic Acid (DNA)
DNA is a molecule. It contains your genes. It is a long chain of smaller molecules called bases that repeat in unique patterns. These patterns act as a code to tell your cells how you should look, act, grow, and adapt to your environment. You are you because of your DNA. An identical copy of this very large molecule is present in the center of every single cell in your body – billions of exact copies. The large DNA molecule is not continuous. It is actually in 23 pieces called chromosomes. Each living thing has a unique number of chromosomes – humans have 23.