The genetic information of an organism is stored in the chemical structure of the DNA. Complete the following paragraph to describe the structure of DNA. DNA is an organic molecule called a and is made of up of units called . Each nucleotide consists of a sugar, a , and four nitrogenous bases. The four nitrogenous bases are , thymine, guanine, and cytosine. When nucleotides link together, they form a strand of DNA with a sugar phosphate backbone. But, DNA actually consists of DNA stands forming a double helix in which the nitrogenous bases are of one another. Adenine forms weak hydrogen bonds with , and forms bonds with cytosine. The order of the in the DNA molecule is how the information is stored.