Assertion: embryo's cell | /r/CapableOf | call the blastula
Facets:
Source sentences:
text: Subsequent cleavages produce a hollow ball comprised of thousands of cells called the blastula, which contains a fluid-filled cavity, the blastocoel.
text: The gastrula develops from the hollow, single-layered ball of cells called a blastula which itself is the product of the repeated cell division, or cleavage, of a fertilized egg.
text: By the next day, continued cleavage has produced a hollow ball of thousands of cells called the blastula.