Embryonic development | Anatomy homework help

In a one to two page paper, give an overview of the embryonic stage of development. 

• Describe the ectoderm, mesoderm, and endoderm and their associated structures. 
• Discuss the structure and function of the embryonic disk. 
• Describe embryo development and the role of chorionic villi. 
• Include any environmental factors that may cause malformations in the developing embryo.