Genes encode for proteins

The DNA can be divided into genes and other kinds of DNA. Each gene contains the information that codes for a particular protein. Different parts of the body have their distinct characteristics because of the kinds of proteins they are made of.

To a crude but workable approximation, then, bodies are built from proteins. Skin, for example, is mainly made of a protein called keratin; oxygen is carried in red blood cells by a protein called hemoglobin. It is ultimately by coding for proteins that DNA enables the egg cell to develop into an adult body.

Figure: the transfer of information in a cell.