The inner cell mass is what eventually forms the embryo. During development, the embryo differentiates into various types of cell layers. Which of the following is NOT one of them?
(A) Cell morula
(B) Hypoblast
(C) Blastomere
(D) Polar body

Embryogenesis is a carefully timed and well-organized process. As a single-celled zygote divides and grows into hundreds and thousands of cells, a process called differentiation occurs wherein certain areas of the embryo become specialized to become different types of tissue. As differentiation continues, the level of specificity increases, and the cell potency decreases until highly specialized unique tissues and organs develop. The figure below shows 12 stages of development of human embryos.

Transcribed Image Text:

1 fertilized 6 polar 2 body 10 blastomere O ectoderm- egg zona hatching 3 8-cell zygote cell adhesion 7 8 invades uterine wall 11 mesoderm endoderm mesoderm forms o 4 mesoderm spreads 16-cell morula cell mass differentiates -epiblast trophoblast- 5 inner cell mass 12 hypoblast trophoblast 9 blastocyst bilaminar disc forms amniotic sac grows