Question

The correct statement regarding RNA and DNA respectively is:
A) The sugar component in the RNA is arabinose and the sugar component in DNA is 2’-deoxyribose
B) The sugar component in the RNA is ribose and the sugar component in DNA is 2’-deoxyribose
C) The sugar component in the RNA is arabinose and the sugar component in DNA is ribose
D) The sugar component in the RNA is 2’-deoxyribose and the sugar component in DNA is arabinose

Answer 1

Hint: The DNA is the genetic material present in our body. It is present inside the nucleus in eukaryotic organisms. RNA is responsible for protein synthesis and is present in the cytoplasm.

Complete answer:
To answer this question, we must know about the structure of DNA and RNA.
Structure of RNA- RNA is made up of ribose sugar, nitrogenous bases and phosphate molecules which are attached by phosphodiester bonds. The nitrogenous bases in RNA are adenine, guanine, cytosine and uracil. Ribose sugar is a normal 5-carbon sugar with oxygen attached to each carbon. The structure of ribose sugar is as follows-
Structure of DNA- DNA is made up of deoxyribose sugar, nitrogenous bases like adenine, guanine, cytosine and thymine. The sugar in DNA 5-carbon is 2’ deoxyribose as one hydroxyl is absent in 2’ position. To the sugar backbone, phosphate and nitrogenous bases are attached by phosphodiester bonds. The structure of 2’deoxyribose in DNA is as follows.

Arabinose- It is a 5 carbon sugar with –CHO functional group. It is the main source of carbon in bacterial cells.

Thus the correct answer is option ‘B’.

Note: The function of sugar backbone in DNA and RNA is that it provides binding sites for nitrogenous bases and phosphate to form phosphodiester bonds. The presence of sugar and phosphate bond provides structural integrity and polarity to both the molecules. It also facilitates binding of protein.