Step 1: Recall what NPC stands for in palynology: Number, Position and Character of pollen apertures. Every term under this system describes some feature of an aperture.
Step 2: Dizonotreme refers to two zones of apertures, catalept and colporate describe aperture types. All three fit inside the aperture-description framework.
Tapetum instead is a cellular layer inside the anther that supplies nutrients to developing microspores. It is a developmental/anatomical term, not an aperture-classification term.
