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': 'Peptidoglycans are present in -a) Gram negative bacteriab) Gram positive bacteriac) Fungid) Protozoa \nSelect and explain. \nA. ac, B. a, C. ab, D. bc', 'role': 'user'}, {'content': 'Answer: C \nExplanation: Cell wall\n\nThe layer just outside the bacterial cytoplasmic membrane is the peptidoglycan layer or cell wall.\nIt is present in both gram-positive and gram negative organisms.\n\n\nThe peptidoglycan layer of gram positive bacteria is thick and contain teichoic acid, while in grant negative bacteria it is thin and does not contain teichoic acid.\nIn gram negative organisms, there is outer cell membrane just outside the thin peptidoglycan layer (cell wall) → Unique feature of gram negative bacteria → dissolution of this layer by ethanol is responsible for grain negativity on gram staining.', 'role': 'assistant'}]