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
Sterols are found in ? 
Select and explain. 
A. Cell wall of Ricketssia, B. Cell membrane of Ricketssia, C. Cell wall of Mycoplasma, D. Cell membrane of Mycoplasma
D: Cell membrane of Mycoplasma
Answer: D: Cell membrane of Mycoplasma 
Explanation: Ans. is 'd' i.e., Cell membrane of Mycoplasma Mycoplasma lack cell wall. They are bounded by triple layered unit membrane that contains sterol. o Thus they require cholesterole and related sterols.