Unless otherwise provided in the articles or bylaws, a majority of the directors currently holding office is a quorum for the transaction of business. Any director who objects at the beginning of a board meeting to the transaction of business because the meeting is not lawfully called or convened and who fails to participate in the meeting after the objection may not be considered as present at the meeting for purposes of determining whether a quorum is present. In the absence of a quorum, a majority of the directors present may adjourn a meeting from time to time until a quorum is present. If a quorum is present when a meeting is properly convened, the directors present may continue to transact business until adjournment, even though the withdrawal of a number of directors originally present leaves less than a quorum.