has_string biological sequence A linear ordering of units representing monomers of a biological macromolecule (e.g. nucleotides in DNA and RNA, amino acids in polypeptides). state biomacromolecular sequence VMC:State GENO defines three levels of sequence-related artifacts, which are distinguished by their identity criteria. 1. 'Biological sequence' identity is dependent only on the ordering of units that comprise the sequence. 2. 'Sequence feature' identity is dependent on its sequence and the genomic location of the sequence (this is consistent with the definition of 'sequence feature' in the Sequence Ontology). 3. 'Qualified sequence feature' identity is additionally dependent on some aspect of the physical context of the genetic material in which the feature is concretized. This third criteria is extrinsic to its sequence and its genomic location. For example, the feature's physical concretization being targeted by a gene knockdown reagent in a cell (e.g. the zebrafish Shha gene as targeted by the morpholino 'Shha-MO1'), or its being transiently expressed from a recombinant expression construct (e.g. the human SHH gene as expressed in a mouse Shh knock-out cell line), or its having been epigenetically modified in a way that alters its expression level or pattern (e.g. the human SHH gene with a specific methylation pattern). 'Sequences' differ from 'sequence features' in that instances are distinguished only by their inherent ordering of units, and not by any positional aspect related to alignment with some reference sequence. Accordingly, the 'ATG' translational start codon of the human AKT gene is the same *sequence* as the 'ATG' start codon of the human SHH gene, but these represent two distinct *sequence features* in virtue of their different positions in the genome. sequence feature location biological sequence or set sequence_feature