Chorion is:-
High-Yield Explanation
Somatotropic mesoderm along with cytotrophoblast is called chorion. Somatopleuric layer lines the cyto-trophoblast and amnion; and splanchno pleuric layer covers the primary yolk sac. The extra embryonic coelom divides the extra embryonic mesoderm into somatopleuric and splanchnopleuric layers.