What does DNA do?

DNA contains the instructions needed for an organism to develop, survive and reproduce. To carry out these functions, DNA sequences must be converted into messages that can be used to produce proteins, which are the complex molecules that do most of the work in our bodies.
A baby forming in its mother’s womb must develop from a single fertilized egg into a complex being having trillions of cells at the time of birth. A full-grown adult has about 30 trillion cells, but the growth in size is nothing compared to the intricate task of developing bones, organs, skin, intelligence and emotions from a single cell.