All employees to whom this subpart applies shall be governed by merit system rules and regulations governing dismissals, suspensions, layoffs, and terminations prescribed in this subpart, administered by the merit system board, the creation of which is provided for in Section 45–47–231.23. Presently employed persons shall remain in their respective employments during good behavior; but nothing herein shall be construed to prevent or preclude the removal of such an employee for cause in the manner hereinafter provided and such employees shall be subject to all the provisions of this subpart.