embryosis

Embryosis is the formation of an embryo. There are two main steps to this process: blastulation, and gastrolation. The begining of this process is the sperm and egg cell fusion to form a zygote. This is when the genetic material merges and all cells are pluripotent. Next there is clevage, compaction, and differentiation forming the blastocyte. The overall size of the blastocyte is not much bigger than the zygote because of compaction. There are many more cells in the blastocyte because of clevage, and some differentiation between the inner cell mass and surrounding cells. Gastrolation is the formation of three distinct layers in the blastocyte which will differentiate. The top layer is the ectoderm, the middle layer is the mesoderm, and the bottom layer is the endoderm. The ectoderm differentiates into the nervous system and the skin. The mesoderm differentiates into the muscles; the endoderm differentiates into the internal organs. This process is virtually the same for all mamals. The outcome is very different because of the genetic information fused, resulting in a wide range of organisms.