Here's why:

* Genetic Information: DNA contains the genetic instructions for building and maintaining an organism. It acts like a blueprint, specifying the order of amino acids in proteins, which in turn carry out a wide range of functions in the cell.

* Transcription and Translation: DNA's information is transcribed into RNA (ribonucleic acid), which is then translated into proteins. This process ensures that the instructions in DNA are used to create the necessary components for cell function.

* Regulation of Gene Expression: DNA doesn't just provide instructions; it also regulates when and how those instructions are used. Different genes can be turned on or off depending on the cell's needs and environmental factors.

While DNA is the master blueprint, it's important to note that RNA plays a crucial role in carrying out these instructions and ensuring the proper functioning of the cell.