The Legislature may provide by law that the Board of Regents of the State University and boards of trustees or managers of the educational, eleemosynary, and penal institutions of the State, and such boards as have been, or may hereafter be established by law, may be composed of an odd number of three or more members who serve for a term of six (6) years, with one-third, or as near as one-third as possible, of the members of such boards to be elected or appointed every two (2) years in such manner as the Legislature may determine; vacancies in such offices to be filled as may be provided by law, and the Legislature shall enact suitable laws to give effect to this section. The Legislature may provide by law that a board required by this constitution be composed of members of any number divisible by three (3) who serve for a term of six (6) years, with one-third of the members elected or appointed every two (2) years.