Section 72. The city council shall have and exercise all the legislative powers of the city, except as such powers are reserved to the school committee and to the qualified voters of the city herein and in sections one to forty-five, inclusive, and the city council and its members shall, severally or collectively, have and possess, and shall themselves or through such officers as they may elect or appoint, exercise all the other powers, rights and duties had, possessed or exercised, immediately prior to the adoption of this plan, by the mayor, board of aldermen, common council, and all other boards, commissions and committees of the city and their members, severally or collectively, except such as are in sections one to forty-five, inclusive, conferred upon the school committee, or are otherwise provided for in sections sixty-four to seventy-eight, inclusive.