This is a real-world medical entrance exam question, please give the true answer based on the question and selection. Topic name: General, Subject name: Microbiology
Which of the following is seen in both prokaryotes and eukaryotes: 
Select and explain. 
A. Mitochondria, B. Ribosome, C. Endoplasmic reticulum, D. Lysosomes
B: Ribosome
Answer: B: Ribosome 
Explanation: Ans: b (Ribosomes) Ref: Ananthanarayan, 7th ed, p. 7Ribosomes are present in both prokaryotic and eukaryotic cells. ProkaryoticEukaryoticSizeSmallLarge 1000 to 10,000 timesCell wallRigidMembrane of lipid bilayerNucleusNot definedWell definedOrganellesNilSeveral-mitochondria lysosome etc.Muramic acidPresentAbsentSterolsAbsentPresentChromo somesOne (circular)More than one( linear)