Q. Which one of the following is an incorrect combination?

 2961  178 AIIMSAIIMS 2015Biomolecules Report Error

Solution:

Adenine (A), guanine (G), cytosine (C), thymine (T) and uracil (U) are all nitrogenous bases, whereas cytidine is a nucleoside i.e., a combination of a nitrogenous base (cytosine) with a pentose sugar (ribose).