This is a real-world medical entrance exam question, please give the true answer based on the question and selection. Topic name: Molecular Genetics, Subject name: Biochemistry
A nucleoside consists of: 
Select and explain. 
A. Nitrogenous base, B. Purine or pyrimidine base + sugar, C. Purine or pyrimidine base + phosphorous, D. Purine + pyrimidine base + sugar + phosphorous
B: Purine or pyrimidine base + sugar
Answer: B: Purine or pyrimidine base + sugar 
Explanation: Ans. B. Purine or pyrimidine base + sugarposition of nucleotides = Sugar + Base + Phosphate Composition of nucleosides = Sugar + Base. No phosphate is present.