This is a real-world medical entrance exam question, please give the true answer based on the question and selection. Topic name: general microbiology, Subject name: Microbiology
[{'content': 'Teichoic acid is present in the cell wall of \nSelect and explain. \nA. Gram positive bacteria, B. Gram negative bacteria, C. Acid fast bacteria, D. All of the above', 'role': 'user'}, {'content': 'Answer: A \nExplanation: Teichoic acids, which are polymers of polyribitol-phosphate, are cross-linked to the peptidoglycan and can be antigenic. They are impoant in cell wall metabolism. Antiteichoic acid antibodies detectable by gel diffusion may be found in patients with active endocarditis caused by S aureus.ComponentsGram-PositiveGram-NegativeColor of GramStained CellPurpleReddish-pinkRepresentativeGeneraBacillus,Staphylococcus,StreptococcusEscherichia,Neisseria,PseudomonasPeptidoglycanThick layerThin layerTeichoic acidsPresentAbsentOuter membraneAbsentPresentLipopolysaccharide(endotoxin)AbsentPresentPorin proteinsAbsentPresent; allow passage ofmolecules through outermembranePeriplasmAbsentPresentRef: Jawetz; 27th edition; Page no: 23', 'role': 'assistant'}]