The tiny ball of 16 cells found freely floating in the uterine cavity is called a ________.
A) blastocyst
B) zygote
C) morula
D) placenta
E) trophoblast

Question

Quizplus · Accepted Answer

At this stage, the developing embryo is a morula, which is a ball of approximately 16 cells. It is too early for the embryo to have formed into a blastocyst, which occurs when the morula has differentiated into two distinct cell types (inner cell mass and trophoblast). A zygote is the fertilized egg immediately after sperm and egg fusion. The placenta and trophoblast form later, during embryonic development.

The Tiny Ball of 16 Cells Found Freely Floating in the Uterine