Long chains of nucleotides are called polynucleotides , and short chains of nucleotides are called oligonucleotides . RNA only has the sugar ribose, and DNA only has the sugar deoxyribose. The sequence is genetic information . RNA or DNA sequences may be prefixed with r or d if not understood from context. Features of the Model for B-form DNA Two strands.
Strands are antiparallel.
Helix rise per base pair is 0.34 nanometers. Ten base pairs per helical turn. Phosphates are on the outside of the molecule. Base pairs are in the inside of the molecule stacked close to each other. Inside cells, B-DNA has an average of 10.5 base pairs per helical turn.