(a)   Except as otherwise provided by this Charter or by ordinance, each board and commission shall be advisory in character. The selection of board or commission members, their terms, responsibilities, authority, policies, removal and other matters concerning each board and commission shall be as established by ordinance.
   (b)   The appointment of any board or commission member who is required by ordinance to be appointed by the Board of Trustees shall require the affirmative vote of a majority of the entire Board.
   (c)   Unless otherwise provided by ordinance, the members of each board and commission shall serve without compensation, but may be paid authorized expenses actually incurred in the performance of the duties of office.
   (d)   No board or commission shall hold any executive session except in accordance with procedures which shall be consistent with those established in Section 3.4 and only for the purposes specified in Section 3.4 of this Charter.