Final answer:
The skin cells originate from the ectoderm germ layer, which also develops into the nervous system and epidermis. The mesoderm creates muscle and connective tissues, and the endoderm forms the gastrointestinal lining and other internal organs.
Step-by-step explanation:
The skin cells are formed from the ectoderm germ layer. This germ layer is one of three primary germ layers—ectoderm, mesoderm, and endoderm—that give rise to all adult tissues and organs during embryonic development. The ectoderm specifically gives rise to both the nervous system and the epidermis, which includes structures such as hair and nails. In contrast, the mesoderm gives rise to muscle cells, connective tissue, as well as the heart and blood vessels, while the endoderm goes on to form the epithelial lining of the gastrointestinal tract and other internal organs such as the liver and pancreas.