Assertion: nucleolus's membrane | /r/CapableOf | become elaborate pore structures
Facets:
value: increasingly
type: DEGREE
Source sentences:
text: A more recent proposal, the exomembrane hypothesis, suggests that the nucleus instead originated from a single ancestral cell that evolved a second exterior cell membrane; the interior membrane enclosing the original cell then became the nuclear membrane and evolved increasingly elaborate pore structures for passage of internally synthesized cellular components such as ribosomal subunits.