Structurally, DNA and RNA are very similar. They're both composed of a backbone of sugar, a phosphate group and a chemical base. However, the sugar in DNA is a deoxyribose sugar and the sugar in RNA is a ribose sugar. In DNA, the chemical bases are; Adenine (A), Thymine (T), Guanine (G), and Cytosine (C). The bases in RNA are very similar except the Thymine (T), is replaced by Uracil (U). The bases form the pairing of; A to T/U, and G to C. DNA forms a double strand and coils into a double helix via hydrogen bonding. Whereas, RNA is a single stranded molecule due to the extra hydroxyl group on the ribose sugar.