Each of the 100 trillion cells that make up our bodies comes with its own complete set of instructions for building us, much like a cookbook. Our genome, which consists of DNA, is a set of instructions for how to live. All the cells in your body, whether they're skin cells or liver cells, have this same set of instructions inside of them.
DNA is the material that makes up the blueprints for our genome. DNA contains a special chemical code that directs our physical and mental development and keeps us healthy.
The DNA code is based on the sequence of the four nucleotide bases adenine, cytosine, guanine, and thymine, or A, C, G, and T for short.
DNA is shaped like a double helix, a twisting structure.
A cell's chromosomes are made up of coiled up single strands of DNA. Chromosomes are found in the nucleus of every one of your cells. Genes are constructed by the "reading" of segments of DNA from our chromosomes.
Eye colour and height, for example, are just two of many traits that are determined by genes. The DNA of every living creature is different.
The human genome is made of 3.2 billion bases of DNA but other organisms have different genome sizes.