Assertion: embryo's cell | /r/HasProperty | blastocyst
Facets:
Source sentences:
text: Embryonic stem cells (often referred to as ES cells) are stem cells that are derived from the inner cell mass of a mammalian embryo at a very early stage of development, when it is composed of a hollow sphere of dividing cells (a blastocyst).
text: They are made from cells found in very early human embryos, called blastocysts.
text: The zygote divides and becomes a collection of cells known as a blastocyst.