1. The government and control of an urban school district is vested in a board of seven directors.
2. Except as provided in section 162.563, each director shall be a voter of the district who has resided within this state for one year next preceding the director's election or appointment and who is at least twenty-four years of age. All directors, except as otherwise provided in sections 162.481, 162.492, and 162.563, shall hold their offices for six years and until their successors are duly elected and qualified. All vacancies occurring in the board shall be filled by appointment by the board as soon as practicable, and the person appointed shall hold office until the next school board election, when a successor shall be elected for the remainder of the unexpired term. The power of the board to perform any official duty during the existence of a vacancy continues unimpaired thereby.