Seeing a blue cup when the cupboard contains blue mugs and non-blue cups, but no blue cups is referred to as (a)n

Seeing a blue cup when the cupboard contains blue mugs and non-blue cups, but no blue cups is referred to as an illusory conjunction.
Illusory conjunctions are psychological effects in which participants combine features of two objects into one object. There are visual illusory conjunctions, auditory illusory conjunctions produced by combinations of visual and tactile stimuli.  

Organism, organ system, organs, tissue, cells