Question

One of the characteristics of DNA is
A. Uracil
B. Deoxyribose sugar
C. Single strandedness
D. The ability of protein synthesis

Answer 1

Hint: One of the important characteristics of DNA that differentiates it from RNA is the presence of a different sugar. DNA has a slightly different ribose sugar that lacks one oxygen atom.

Complete answer: DNA is a polymer of deoxyribonucleotides or it is a polynucleotide chain that is made up of three components- nitrogenous base, deoxyribose (pentose sugar), and a phosphate group. Some of the salient features of double-stranded DNA are-
1. It has two polynucleotide chains made up of sugar backbone and the bases project out. The chains are in antiparallel polarity.
2. The nitrogenous bases in the two strands are joined by the hydrogen bonds forming base pairs. Two hydrogen bonds are present between adenine and thymine whereas three hydrogen bonds are present between cytosine and guanine.
3. The two nucleotide chains of DNA are in a right-handed fashion and the pitch of the helix is about 3.4nm containing about ten base pairs and the distance between each base pair is about 0.34 nm.
4. The sugar in DNA is deoxyribose whereas RNA has ribose sugar. In the second carbon position, ribose sugar has an additional oxygen molecule.
Hence, the correct option is (B)-Deoxyribose sugar.

Note: The ribose sugar of the DNA lacks one oxygen atom at the second carbon position of ribose and therefore, it is known as deoxyribose sugar. Pentose sugar is present in the nucleic acid.