Question

Which one is not applicable to RNA?
A. Complementary base pairing.
B. 5’ phosphoryl and 3’ hydroxyl ends.
C. Heterocyclic nitrogenous bases.
D. Chargaff's rule.

Answer 1

Hint: RNA is called a ribonucleic acid. It helps in the synthesis of proteins in our body. It is transcribed from DNA molecules. It is the same as DNA but RNA is single-stranded and DNA is double-stranded. RNA also functions as an enzyme as it helps with many chemical reactions in the body.

Complete answer:
Chargaff's rule states that the DNA from any cell should have a ratio of 1:1 for pyrimidine and purine bases. This means that the amount of adenine should be equal to thymine and guanine should be equal to cytosine. RNA is a single-stranded molecule which defies this law as there is no pairing between the bases. Another difference between DNA and RNA is that instead of thymine, uracil is present in RNA. There are three types of RNA:
a. tRNA is known as transfer RNA. It helps the body in choosing the correct amino acid. It forms a link between the messenger RNA and amino acids.
b. rRNA is known as ribosomal RNA. It plays a very important role in the synthesis and translation of mRNA to proteins. It is of two types; 70S and 80S.
c. mRNA is also known as messenger RNA. It helps to move the genetic material into the ribosomes along with instructions about proteins required by the cells of our body. It plays a vital role in the process of transcription and protein synthesis.
All these molecules explained above are single-stranded in nature. Chargaff’s rule is not applicable to these molecules.
Hence, the correct answer is option D.

Note: Chargaff's second rule appears to be the consequence of a more complex parity rule: within a single strand of DNA any oligonucleotide is present in equal numbers to its reverse complementary nucleotide. Because of the computational requirements, this has not been verified in all genomes for all oligonucleotides.