has part has part has_part characteristic of has modifier abnormal nasal placode morphology absent nasal placodes MPheno.ontology absent olfactory placodes absence of the paired ectodermal placodes that come to lie in the bottom of the olfactory pits as the pits are deepened by the growth of the surrounding medial and lateral nasal processes; the nasal placode gives rise to the olfactory epithelium of the nose MP:0006293 abnormal absent olfactory placode