(1) Upon the date an optional unified form of county government becomes effective, the following officials shall exercise the powers and functions as provided by law, unless other powers or functions are delegated to an official by the board of county commissioners:

    (a) The sheriff.

    (b) The clerk-register or clerk and the register of deeds.

    (c) The treasurer.

    (d) The prosecuting attorney. If a county employs an attorney under 1941 PA 15, MCL 49.71 to 49.73, the prosecuting attorney shall not act relative to 1941 PA 15, MCL 49.71 to 49.73.

    (e) The drain commissioner.

    (f) The boards of county road commissioners. Members of the county road commission shall be appointed as provided under section 6 of 1909 PA 283, MCL 224.6. In a county with a population of 1,000,000 or more, the board of county road commissioners shall not exceed 3 members.

    (2) The officials named in subsection (1) shall be elected or appointed in the manner and for a term as provided by law.