The council shall elect from among its members a speaker and such other officers as it deems appropriate. The speaker shall preside over the meetings of the council. During any period when the public advocate is acting as mayor, or when a vacancy exists in the office of the public advocate, the speaker shall act as public advocate pending the filling of the vacancy pursuant to subdivision c of section twenty-four, and shall be a member of every board of which the public advocate is a member by virtue of his or her office.