The officers of a cooperative shall consist of a president, one or more vice-presidents, a secretary, and a treasurer, who shall be elected annually by the board of trustees. The cooperative may elect a chairperson of the board who shall be elected by and from the board of trustees. The offices of secretary and treasurer may be held by the same person. The board of trustees may also elect or appoint such other officers, agents, or employees as it shall deem necessary or advisable and shall prescribe the powers and duties thereof. Any officer may be removed from office and his successor elected in the manner prescribed in the bylaws.