Anatomy Development period- week 1,2,3,4 80568dd6 Foldings of embryo occurs at:- A 3rd week B 4th week C 5th week D 6th week High-Yield Explanation At the end of 3rd week the embryonic area shows the development of head fold, tail fold and two lateral folds. These folds conve the flattened germ disc to cylindrical embryo.