Question 1
The outer layer of cells that will form the structures that will provide protection and nourishment for the newly formed organism is the ____.
◦ umbilical cord
◦ placenta
◦ embryonic disk
◦ trophoblast
Question 2
The outer layer of the embryonic disk will become ____.
◦ the brain and spinal cord
◦ skin, hair, nails, and the nervous system
◦ muscle, bones, and the circulatory system
◦ the digestive and respiratory systems