The board shall meet at least once a year to conduct its business and to elect a chair. Additional meetings must be held as necessary to conduct the business of the board and may be convened at the call of the chair or a majority of the board members. Four members of the board constitute a quorum for the transaction of business. The board has the power to make and adopt rules and a code of ethics consistent with law necessary for the enforcement of its authority, the performance of its duties and the governing of the practice of chiropractic, but a rule or code of ethics may not be made that is unreasonable or contravenes this chapter. [2007, c. 402, Pt. H, §4 (RPR).]