Question

Which of the following statements is not true about RNA?
A) It has always double-stranded a-helix structure.
B) It usually does not replicate.
C) It is present in the nucleus of the cell.
D) It controls the synthesis of protein.

Answer 1

Hint: RNA stands for ribonucleic acid. It is a nucleic acid that is important in cellular processes like cell division, growth, and aging. The RNA and DNA are chemically similar except the nature of sugar. It has a single helical structure and it carries important information about the amino acid sequence.

Complete step by step answer:
DNA and RNA are the polymers of the corresponding sugar and nucleotides.
RNA stands for the ribonucleic acid and the DNA is deoxyribonucleic acid.
DNA and RNA are chemically similar except the nature of sugar. The DNA has a deoxy sugar in the nucleotide.DNA and RNA differ in the size.
The molecules of RNA are smaller and found outside of the nucleus in the cytoplasm.
The RNA exists as a single-stranded molecule. DNA is designed to store the genetic information for the next generation. So it needs to be stable and resist oxidation. Therefore the double helix structure of DNA is a structure to store the information.
Unlike DNA, RNA is not a double-helical structure.RNA is never meant to live long. It has the same template as that of the DNA which is further taken to the ribosomes where the protein transcription is exchanged.RNA is the template of DNA that can be used and then disintegrated. It has a single strand as it combines with the DNA by having half of its sequence.
It is a well-known fact that DNA replicates itself in the cell. However, the replication of RNA does not take place. In the theory, RNA should replicate with the help of protein but this does not happen. The self-replication of RNA takes place only in a few cases. In the case of viroid or viruses they replicate in the nucleus and then transfer to the organs but this self-replication is not observed for cellular RNA.
RNA is found in the cytoplasm but it is synthesized in the nucleus. It is then transferred through the body.
The DNA has the genetic code which makes the RNA and RNA contain the code to make the primary sequence of the amino acid to make proteins.
Thus the option (B) and (D) are true statements about RNA.
RNA is present in the cytoplasm and it has a single-stranded $\alpha $ helix structure. Therefore the option (A) and (C) are the incorrect statements.

Hence, the correct option is (A) and (C).

Note: The DNA and RNA only differ in the sugar. RNA is synthesized in the nucleus but it does not present in the nucleus. This can be confusing. Always remember that RNA is present in the cytoplasm but synthesized in the nucleus.