<prompt> Metanephros develops during which week of embryonic development?4th5th6thNone of the above  <response>: The third urinary organ, the metanephros, or permanent kidney, appears in the fifth week. Its excretory units develop from metanephric mesoderm in the same manner as in the mesonephric system. Ref: Langmans embryology 11th edition Chapter 15. 