<prompt> HERS is formed by:Cells of stratum intermedium.Cells of IEE.Cells of the cervical loop.Cells of the apical periodontium.  <response>: Formation of the root sheath begins with the formation of the Hertwigs root sheath. Hertwigs root sheath is the apical extension of the cervical loop of enamel epithelium. At the cervical loop, the stratum intermedium is lost and the outer and the inner enamel epithelium come in contact. 