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
Which of the following viruses possesses DNA a capsid with icosahedral symmetry and no lipid envelope 
Select and explain. 
A. Herpesvirus, B. Adenovirus, C. Poxvirus, D. All
B: Adenovirus
Answer: B: Adenovirus 
Explanation: Ans. is 'b' Adenovirus Read the following facts and this question will seem very easy : . All nonenveloped viruses (whether DNA or RNA) have icosahedral symmetry. . Nonenveloped DNA viruses PAP - PApova, Adeno, PArvo . Nonenveloped RNA viruses -4 PCR - Picorna, Calci, Reo. Also know . All DNA viruses (whether enveloped or nonenveloped) have icosahedral symmetry except poxvirus which has complex symmetry. . No DNA virus has helical symmetry. . RNA viruses have either icosahedral or helical symmetry : Icosahedral symmetry --> Nonenveloped RAN viruses (PCR --> Picorna, Calci, Reo) and Retro, Flavi, Toga, (Remember - RFT). Helical symmetry --> Rest of the RNA viruses.