Which layer of the embryo is primarily responsible for the formation of connective tissues?

The mesoderm is the layer of the embryo that primarily gives rise to connective tissues. During embryonic development, the mesoderm differentiates into various structures, including muscles, bones, and other connective tissues that play vital roles in providing structural support and integrity to the body. It also contributes to the development of the cardiovascular system, dermal layers of skin, and the urogenital system.

In contrast, the ectoderm primarily develops into the skin and nervous system, while the endoderm mainly forms internal structures, including the lining of the gastrointestinal tract and associated organs. The periderm is a temporary layer that covers the embryo but does not directly contribute to the formation of connective tissues. Thus, the mesoderm is indeed the layer essential for the development of connective tissues in the body.