<prompt> Mononuclear phagocytes are produced by -ThymusSpleenBone marrowLiver  <response>: The monocyte is formed in the bone marrow and transpoed by the blood ; it migrates into the tissues, where it transforms into a histiocyte or a macrophage. Reff: Ananthanarayanan Panikers textbook of microbiology 9th edition pg:137 