This is a real-world medical entrance exam question, please give the true answer based on the question and selection. Topic name: Bacteriology, Subject name: Microbiology
[{'content': 'Inveed fir tree appearance is characteristic of \nSelect and explain. \nA. Bacillus anthrax, B. Hemophilus influenzae, C. Yersinia pestis, D. Brucella', 'role': 'user'}, {'content': "Answer: A \nExplanation: Anthrax bacilli is gram-positive and is found singly, in pairs or in sho chains. On gelatin stab culture, a characteristic inveed fir tree appearance is seen in the case of anthrax bacilli, with slow liquefaction commencing from the top. On blood agar, the colonies are non-hemolytic, though occasional strains produce a narrow range of hemolysis. In broth, growth occurs as floccular deposits, with little or no turbidity. Reference: Textbook of Microbiology; Anathanarayan and panicker's; 10th edition; Page no: 251", 'role': 'assistant'}]