Question

The presence or absence of hydroxy group on which carbon atom of sugar differentiates RNA and DNA.

(a) 1^st 

(b) 2^nd

(c) 3^rd 

(d) 4^th

Answer 1

(b) : The sugar molecule found in RNA is D-ribose while the sugar in DNA is D-2-deoxyribose. The sugar D-2-deoxyribose differs from ribose only in the substitution of hydrogen for an – OH group at 2-position as shown in figure.