<prompt> First carbon of pentose sugar of nucleic acid joinsN-9 of pyrimidineN-1of pyrimidineN-1 of purineNone of the above  <response>: Pentose sugar present in DNAs is deoxyribose and in RNAs it is ribose. A pentose sugar ribose or deoxyribose is linked to a nitrogenous base purine or pyrimidine covalent N-glycosidic bond to form nucleoside. This linkage joins the Carbon-I of pentose sugar with nitrogen-9 of the purine base or nitrogen-I of pyrimidine base. 