What would happen to progesterone and estrogen levels if the trophoblast in an implanted embryo failed to secrete hCG? Describe the major events of embryonic development. Discuss the process of...

trophoblast in an implanted embryo failed to secrete hCG?

Describe the major events of embryonic development.

Discuss the process of gastrulation and embryonic folding.

Describe organogenesis, focusing on ectoderm, mesoderm, and

endoderm differentiation.