The board shall consist of not less than three nor more than seven members as may be provided by charter provision or ordinance, a majority of whom shall constitute a quorum for the transaction of business, except as hereinafter in this article provided. Each member of the board must be a resident and freeholder of the city. It may be provided either by charter provision or by ordinance for the appointment of the members thereof by the governing body, but unless and until such provision is made, the members of the board shall be elected by the qualified voters of the city at appropriate regular municipal elections. Membership on the governing body may not disqualify any member for election to the board. If provision is made for the appointment of members as aforesaid and the board consists of three or four members, one member of the governing body, if otherwise qualified, may be appointed by the governing body; if the board consists of five members not more than two members of the governing body so qualified may be so appointed and if the board consists of six or seven members not more than three members of the governing body so qualified may be so appointed. The term of the board membership of any member of the governing body so appointed shall continue during his or her term as a member of the governing body and until his or her successor is appointed or elected and qualified. The terms of other appointed or of elected members shall be for six years, and until their successors have been duly appointed or elected and qualified: Provided, That notwithstanding the fact that there be no charter provision or ordinance for appointment of the members of the board, the governing body of the city shall appoint the members of the first board, such appointees to serve, one for a term of six years, one for a term of four years, and one for a term of two years. The date upon which the terms of the board members shall begin shall be specified by ordinance. When any member of the board, during his or her term of office, shall cease to be a resident and freeholder of the city, he or she shall thereby be disqualified as a member of the board and his or her office shall thereupon become vacant.