Question

The structure of DNA and RNA are similar in respect to which of the given options?
A. Both molecules are made of the same 5 carbon sugar
B. Both molecules are composed of the same four nitrogenous bases
C. The nucleotides of both molecules contain a phosphate group
D. Both molecules are double-stranded which are anti-parallel in directionality

Answer 1

Hint: DNA gets transcribed to form RNA and the RNA is further translated to form the proteins. The DNA and RNA synthesis involves the concept of complementary base pairing. In RNA thymine is replaced by Uracil.

Complete answer: DNA is the genetic material that is passed from one generation to another. The transcription of RNA leads to the formation of RNA. RNA is usually single-stranded but various viruses have been reported to possess double-stranded RNA as a genomic content.
Let us consider each of the options individually.
1. Both the DNA and RNA chains are made up of the same pentose sugar that is 5 carbon compounds. The only difference is that DNA has deoxyribose sugar at 2’end where the hydrogen group is replaced by the hydroxyl group.
2. Both molecules are composed of the same four nitrogenous bases
In RNA thymine is replaced by Uracil. Other than these nitrogenous bases all three base pairs Adenine, Guanine, Cytosine are common.
3. The nucleotides of both molecules contain a phosphate group
The phosphate group is attached to the 5` -Carbon sugar of the deoxyribose and ribose sugar. The nucleotides are attached to the 1` carbon of the pentose sugar.
4. Both molecules are double-stranded which are anti-parallel in directionality
DNA is a double-stranded molecule and RNA is a single-stranded molecule.
Moreover, the antiparallel direction is coined on the basis of the direction of the synthesis of RNA or to differentiate the coding and non-coding strand.

Therefore, the correct option is Option A.

Note: DNA and RNA synthesis occur based on complementary base pairing.
The pentose sugar in DNA and RNA is similar except at the 2` position.