to become blastocoelic fluid. hydrostatic pressure of the fluid creates a large cavity in the morula called a blastocoel. embryoblast cells also known as the inner cell mass form a compact mass of cells at the embryonic pole on one side of the cavity that will go on to produce the embryo proper. the embryo is now termed a blastocyst. the trophoblasts will eventually give rise to the embryonic contribution to the placenta called the chorion. a single cell can be removed from a pre-compaction eight-cell embryo and used for genetic screening, and the embryo will recover.