Stages





S T A G E S

1) __**Fertilization**__ - The process of sperm joining an egg.

2) __**Zygote**__ - The Fertilized egg.

3) **__Cleavage__** - cells split into 2 and then into four.

4) **__Morula__** - The solid ball of about 64 cells, four days after fertilization.

5) **__Blastula__** - An inner cavity that forms as morula grows.

6) __**Implantation**__ - When the embryo secretes enzymes that digest a path into the soft tissue.

7) **__Gastrulation__** - The cell migration that forms the three layers : ectoderm, mesoderm, and endoderm.

8) **__Gastrula__** - Where gastrulation occurs.

9) **__Embryo__** - The forming fetus.

10) **__Fetus__** - The embryo after 8 weeks of development.