During a human pregnancy, implantation begins at which stage?

Question

Quizplus · Accepted Answer

Implantation, the process by which the fertilized egg attaches to the uterine wall, begins during the blastocyst stage, which is when the embryo has developed into a hollow ball of cells with an inner cell mass and an outer layer of cells. The zygote, early cleavage, and morula stages occur prior to the blastocyst stage, while the fetus stage occurs much later in the pregnancy.

During a Human Pregnancy, Implantation Begins at Which Stage