The Phase During Which Embryonic Cells Arrange Themselves into Three

Question

The phase during which embryonic cells arrange themselves into three layers is called:
A) cleavage.
B) gastrulation.
C) organogenesis.
D) fertilization.
E) induction.

Accepted Answer

Gastrulation is the process during which embryonic cells organize themselves into three layers: the endoderm, mesoderm, and ectoderm. Cleavage refers to the rapid cell division that occurs immediately after fertilization. Organogenesis refers to the formation of organs, which occurs after gastrulation. Fertilization is the fusion of a sperm and an egg, which occurs at the beginning of embryonic development. Induction refers to the process by which one group of cells directs the development of neighboring cells.