Final answer:
Mesenchyme comes from the mesoderm germ layer, which also gives rise to muscle cells and connective tissue in the body.
Step-by-step explanation:
The mesenchyme comes from the mesoderm germ layer. The three germ layers are the endoderm, the ectoderm, and the mesoderm. The ectoderm gives rise to the nervous system and the epidermis, while the endoderm gives rise to the gut and many internal organs. The mesoderm gives rise to muscle cells and connective tissue in the body.