When the planning commission performs in the capacity as the hearing body, a majority of the commission's membership shall constitute a quorum for the transaction of official business; provided, that a smaller number may adjourn from time to time. Every official act taken by the commission on discretionary items requiring a public hearing shall be by resolution or motion adopted by an affirmative vote of a majority of the membership, except in those instances when one or more members of the commission recuse themselves from a particular case, then a resolution or motion shall be adopted by an affirmative vote of a majority of the membership present. However, failure to obtain such affirmative vote shall not prevent consideration by the commission of other resolutions and motions concerning such item which may subsequently be properly presented. All other official actions taken by the commission shall be by resolution or motion adopted by an affirmative vote of a majority of the quorum, or of the members present, if more members are present than required for a quorum.