Organization: There is hereby created a Board of Adjustment consisting of five (5) members, each to be appointed by resolution of the City Council for a term of two years and removable for cause by the appointing authority upon written charges and after public hearing. Vacancies shall be filled for the unexpired term of any member, whose place becomes vacant for any cause, in the same manner as the original appointment was made. Provided, however, that the City Council may appoint two alternate members of the Board of Adjustment who shall serve in the absence of one or more of the regular members when requested to do so by the Mayor or City Manager, as the case may be, so that all cases to be heard by the Board of Adjustment will always be heard by a minimum number of the four members. The alternate members, when appointed, shall serve for the same period as the regular members, which is for a term of two years, and any vacancy shall be filled in the same manner.