Sec. 551. City Planning Commission. The Board of Commissioners of the City Planning Department shall be known as the City Planning Commission and shall consist of nine members. It shall: (a) give advice and make recommendations to the Mayor, Council, Director of Planning, municipal departments and agencies with respect to City planning and related activities and legislation; (b) make recommendations concerning amendment of the General Plan and proposed zoning ordinances in accordance with Sections 555 and 558; (c) make reports and recommendations to the Council and to other governmental officers or agencies as may be necessary to implement and secure compliance with the General Plan; and (d) perform other functions prescribed by the Charter or ordinance.