(a) prescribe the number of members of an agency or board and the method by which the members are to be chosen, whether by appointment or election, or partly one way and partly the other;

(b) prescribe by-laws for the conduct of the government of an agency or board, including one for the appointment of an executive committee of an agency or board to exercise such powers as may be conferred upon it by the agency or board, and provide that any power so exercised by the executive committee shall be deemed to have been exercised by the agency or board;

(c) provide for the establishment of advisory committees to advise and make recommendations to the agency or board in respect of any matter respecting which the agency or board is empowered to make orders under this Act, the regulations or the plan;

(d) determine the constitution of advisory committees and prescribe the practice and procedure to be followed by such committees;

(e) empower an agency or board to make by-laws not inconsistent with this Act, the regulations or the plan.