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
Lipopolysaccharide structure is characteristic of - 
Select and explain. 
A. Exotoxin, B. Endotoxin, C. Both, D. None
B: Endotoxin
Answer: B: Endotoxin 
Explanation: Endotoxins heat stable lipopolysaccharides which form an integral pa of the cell wall of gram-negative bacteria . Their toxicity depends on the lipid component. They are released only by the disintegration of the cell wall. They cannot be toxoided. They are poor antigens and their toxicity is not completely neutralized by the homologous antibodies. they are active only in relatively large doses. Ref Ananthanarayan & paniker's Textbook of Microbiology 9th edition pg no 74.