information content entity textual sequence of genetic interval The textual sequence refects the order of the nucleotide residue within a gene or a choromsome or any genetic interval. The chromosome includes not only the nucelotide residues interwined into DNA helix but also proteins such as Histone, so we make a distinction that the textual sequence of genetic interval only reflects the primary structure of a genetic interval. a sepcific gene sequence stored in a EntrezGene database the textual sequencial sets of 'A,T,C,G' or 'A,U,C,G' represent the primary structure of a genetic interval. primary structure of biological interval