Early Human Embryonic Development Quiz

Fertilization and Embryonic Development

• Embryos mostly develop in the fallopian tube and migrate to the uterus during development.

Zygote Development

• Rapid synchronized cell division without growth during zygote development results in cleavage.

Fertilization Mechanisms

• The zona pellucida functions to prevent polyspermy during fertilization.

Morula Stage

• Cells at the morula stage are compacted, forming a tight cluster of cells.

Mid-Blastula Transition

• The mid-blastula transition is a brief period of embryonic development characterized by a transition from maternal to zygotic control.

Embryonic Development Checkpoints

• The re-gain of mitotic checkpoints during embryonic development is facilitated by the activation of the zygotic genome.

Natural Fertilization

• Selection for euploid cells begins during natural fertilization at the cleavage stage.

IVF Success

• IVF success to live birth is approximately 2-fold more successful using blastocyst stage than morula stage due to the increased selection of euploid cells.

Trophoblasts

• The main function of trophoblasts during embryonic development is to promote implantation and establish the placenta.

Placenta Formation

• The formation of the placenta during embryonic development begins with the differentiation of trophoblasts.

Bilaminar Disc

• The bilaminar disc functions to establish the embryonic and abembryonic poles of the embryo.

Primitive Streak/Node

• The invagination/migration of epiblast cells at the primitive streak/node results in the formation of the germ layers.