This is a real-world medical entrance exam question, please give the true answer based on the question and selection. Topic name: None, Subject name: Microbiology
[{'content': 'Metachromatic granules are found in -a) Diphtheriab) Mycoplasmac) Gardenella vaginalisd) Staphylococcus \nSelect and explain. \nA. ac, B. bc, C. ad, D. b', 'role': 'user'}, {'content': 'Answer: A \nExplanation: Polypmetahosphate / volutin granules \n\nSome bacteria contain granules composed of polymetaphosphate. They were first described in spirillum volutans, so they were called as Volutin granules.\nThese granules are also known as Babes Ernst granules or polar bodies or metachromatic granules.\nThese granules stain reddish violet with methylene blue or toluidine blue.\nThese granules are strongly basophilic.\nIn the granules, there is stored phosphate in the form of linear chains of inorganic phosphate. These granules represent intracellular phosphate reserve when nucleic acid syntheis does not occur.\nThe phosphate is incorporated into nucleic acid during the synthesis of the latter.\nWhen nucleic acid synthesis is prevented by starvation , the granules accumulate in the cytoplasm. So, volutin metachromatic granules are most frequent in cells grown under conditions of nutritional deficiency (starvation) and tend to disappear when the deficient nutrients are supplied.\nVolutin metachromatic granules are common in\n(i) Corynebacteria diptheriae \xa0 ii) Mycobacteria \xa0iii) Gardenella vaginalis\xa0iv) Spirillum voluants \xa0v) Agrobacterim tumefaciens', 'role': 'assistant'}]