Figure 1.

A section of the Sequence Ontology showing how terms and relationships are used together to describe knowledge about sequence. The kind_of relationships are depicted using arrows labeled with 'i', the part_of relationships use arrows with 'P' and the derives_from relationships with 'd'. By tracing the arrows that connect the terms, different logical inferences can be made regarding what a term 'is' and what are its allowable parts. For example, an exon is a part_of a transcript, a tRNA is a kind_of ncRNA which is a kind_of processed_transcript.