Which of the following embryonic materials is matched with a correct post-natal (after birth) derivative? (Chose the most correct answer.) Solution In the process of Gastrulation 3 germ layers are produced and their derivatives are - Ectoderm- nervous systerm(spine,peripheral nerves and brain),enamel of tooth,epidermis(outer part of skin) Mesoderm- connective tissue and muscle Endoderm- linings of digestive,respiratory,urinary tracts and glands like thyroid,parathyroid,liver and pancreas.