The master copy of genetic information is stored in DNA. DNA stands for deoxyribonucleic acid and it is the molecule that contains the genetic instructions for the development and functioning of all known living organisms. DNA is found in the nucleus of cells in eukaryotes, which include plants and animals. It is organized into structures called chromosomes, which are made up of long strands of DNA. DNA is composed of a sequence of nucleotides, which are the building blocks of DNA. Each nucleotide consists of a sugar molecule, a phosphate group, and a nitrogenous base. The order of these nitrogenous bases along the DNA strand determines the genetic code, which instructs cells on how to produce proteins and carry out other cellular functions. Therefore, DNA is considered the master copy of genetic information and is passed down from generation to generation.