Assertion: zygote's cell | /r/CapableOf | call the trophoblast
Facets:
Source sentences:
text: The blastocyst has an outer-layer of cells called the trophoblast, which will eventually form the protective placenta.
text: As the number of cells grows from 16 to between 40 and 150, the blastocyst differentiates into two layers, an outer sphere of cells called the trophoblast and an inner cell mass called the embryoblast.