<prompt> Which of the following metabolizes arginine?Mycoplasma pneumoniaeMycoplasma genitaliumMycoplasma hominisUreaplasma urealyticum  <response>: M. hominis metabolizes arginine, with the production of potentially cytotoxic amounts of ammonia. Ureaplasmas have been placed in a separate genus because of their unique urease activity; the metabolism of urea also produces ammonia. 