Any person holding administrative office under the city government at the time this charter takes effect shall continue in office and in the performance of his duties until provision shall have been made in accordance therewith for the performance of such duties or the discontinuance of such office. The powers conferred and the duties imposed upon any officer, commission, board or department of the city by the laws of the state shall, if such office, commission, board or department be abolished by this charter, be thereafter exercised and discharged by the office or department designated by the commission unless otherwise provided herein.