Ribo-This is short for ribose and it is a pentose sugar. Contrast this with the sugar group in DNA which is dexoyribose. Nucleic-Refers to the fact that it originates in the nucleus.
DNA is a double helix formed by base pairs attached to a sugar-phosphate backbone. DNA, or deoxyribonucleic acid, is the hereditary material in humans and almost all other organisms.
The DNA structure consists of two chainlike molecules (polynucleotides) that twist around each other to form the classic double-helix. The cell s machinery forms polynucleotide chains by linking together four nucleotides.