1. Unless the articles or bylaws of a corporation, or subsection 3, provide otherwise, regular meetings of the board may be held without notice.
2. Unless the articles, bylaws, or subsection 3 provide otherwise, special meetings of the board must be preceded by at least two days’ notice to each director of the date, time, and place, but not the purpose, of the meeting.
3. In corporations without members, any board action to remove a director or to approve a matter which would require approval by the members if the corporation had members shall not be valid unless each director is given at least seven days’ written notice that the matter will be voted upon at a directors’ meeting or unless notice is waived pursuant to section 504.824.
4. Unless the articles or bylaws provide otherwise, the presiding officer of the board, the president, or twenty percent of the directors then in office may call and give notice of a meeting of the board.