During the period of the embryo, the becomes the nervous system, the becomes the circulatory system, and the becomes the digestive system

Weeks 3-4: three layers form: the ectoderm, the mesoderm, and the endoderm. Neural tube develops and produces neurons. Heart begins beating. Ribs, muscles, and digestive tract form. weeks 5-8: arms and legs develop, then fingers and toes; placenta and umbilical cord function; digestive system develops; liver produces blood cells. 

the answer is false?

1. the energy lost to disorder metabolism     -entropy

2. related to or possessing motion potential     -kinetic

3. all of the chemical reactions in an organism required for maintenance of the processes of life entropy     -metabolism

4. possible; ability to go into action or perform work kinetic     -potential

5. the study of energy and its transformations thermodynamics     -thermodynamics