This is a real-world medical entrance exam question, please give the true answer based on the question and selection. Topic name: General anatomy, Subject name: Anatomy
[{'content': 'The epiblast forms which of the following germ cell layers \nSelect and explain. \nA. Ectoderm, B. Ectoderm ,Mesoderm, Endoderm, C. Mesoderm, Endoderm, D. Ectoderm , Mesoderm', 'role': 'user'}, {'content': 'Answer: B \nExplanation: Epiblast forms all the three germ cell layers - Ectoderm,Mesoderm, Endoderm. After the formation of the primitive streak,the epiblast cells migrate towards the primitive streak. When they arrive at the primitive streak, they become flask shaped, detach from the epiblast and slip beneath the primitive streak. This inward movement is called as Invagination. Some of these cells displace the hypoblast to form embryonic Endoderm ( which is the first layer to form) Some of the invaginated cells then sta occupying the space between the epiblast and the newly formed Endoderm to form Mesoderm. Cells remaining in epiblast form Ectoderm. Ref: Indersingh textbook of Embryology 11 the edition pg 56.', 'role': 'assistant'}]