has_part has part has part composed primarily of UBREL:0000002 composed_primarily_of 'otolith organ' SubClassOf 'composed primarily of' some 'calcium carbonate' uberon composed_primarily_of x composed_primarily_of y if and only if more than half of the mass of x is made from y or units of the same type as y. Chris Mungall x composed_primarily_of y iff: more than half of the mass of x is made from parts of y RO:0002473 material entity material entity axiom holds for all times