Assertion: fern's spore | /r/MadeOf | cellular divisions
Facets:
value: in two different planes
type: LOCATION
value: at right angles
type: MANNER
value: to one another
type: TRANSITIVE-OBJECT
Source sentences:
text: The tetrahedral spore is formed by cellular divisions in two different planes at right angles to one another during meiosis in the spore mother cell.