A Blastocyst Is

Question

A blastocyst is
A)an extraembryonic membrane that forms blood vessels.
B)a solid ball of cells.
C)a hollow ball of cells.
D)a portion of the placenta.
E)the membrane that forms the urinary bladder.

Accepted Answer

A blastocyst is a hollow ball of cells that forms early in embryonic development. It contains an inner cell mass that will develop into the embryo and an outer layer of cells called the trophoblast that will help form the placenta.