<prompt> Acid fastness of tubercle bacilli is attributed to ?Presence of mycolic acidIntegrity of cell wallBoth of the aboveNone of the above  <response>: Ans. is c i.e., Both of the above Acid fastness has been ascribed variously to the presence in the bacillus of the unsaponifiable wax mycolic acid or to a semipermeable membrane around the cell. It is related to the integrity of the cell wall and appears to be a propey of lipid-rich waxy cell wall. Acid fastness is not a propey of lipids alone but depends also on the integrity of the cell wall. - Ananthanarayan 