<prompt> Inveed fir tree appearance on gelatin stab is characteristic of?MycoplasmaBacillus anthracisClostridiumBacteriodes  <response>: Virulent capsulated strains of Bacillus anthracis form rough culture, while avirulent or attenuated strains form smooth colonies. on gelatin stab culture, a characteristic inveed fir tree appearance is seen with slow liquefaction commencing from the top. On blood agar the colonies are nonhemolytic though occasional strains produce a narrow zone of hemolysis .in broth growth occurs as floccular deposits with little or no turbidity REF:Ananthanarayan Panickers Textbook of Microbiology 8th Edition pg no: 243 