The cells of the morula form a hollow ball of cells called a blastocyst.

Question

Quizplus · Accepted Answer

After several rounds of cell division, the cells of the morula will begin to differentiate, forming an inner cell mass and an outer layer of cells. The outer layer of cells will form the trophoblast, which will eventually develop into the placenta, while the inner cell mass will form the embryo. The blastocyst is a fluid-filled hollow ball of cells that is formed when the inner cell mass becomes surrounded by the trophoblast cells.

The Cells of the Morula Form a Hollow Ball of Cells