Explanation

Ectoderm. Fate of three germ layers Mesoderm Dermis of skin, circulatory system, muscles, bones (except facial) Endoderm Lining of $Gl$ tract, lining of lungs, kidney ducts and bladder, thymus, thyroid tonsils Ectoderm Epidermis of skin, tooth enamel, lens and cornea of the eye outer ear Brain and spinal cord, facial bones skeletal muscles in the head All bones are derived from the mesoderm but only facial bones which are derived from the ectoderm