Question

RNA A. incorporates both modificd and unmodified bases during transcription. B. does not crhibit any double-helical structure. C. structures crhibit base stacking and hydrogen-bonded base pairing D. usually contains about \(65-100\) nucleotides. E. does not exhibit Watson-Crick base pairing.

Short answer

Question: Identify the correctness of the following statements about RNA: A. Incorporates both modified and unmodified bases during transcription. B. Does not exhibit any double-helical structure. C. Structures exhibit base stacking and hydrogen-bonded base pairing. D. Usually contains about \(65-100\) nucleotides. E. Does not exhibit Watson-Crick base pairing. Answer: A (True), B (False), C (True), D (False), E (False)

Step-by-step solution

Statement A: Incorporates both modified and unmodified bases during transcription.

This statement is correct. RNA incorporates both modified (e.g., pseudouridine and inosine) and unmodified bases (adenine, guanine, cytosine, and uracil) during transcription.

Statement B: Does not exhibit any double-helical structure.

This statement is false. While it is true that RNA is usually single-stranded, it can still form double-helical structures through intra- or intermolecular base pairing, such as in tRNA or rRNA.

Statement C: Structures exhibit base stacking and hydrogen-bonded base pairing.

This statement is correct. RNA structures can exhibit base stacking, which contributes to the stability of the molecule, and hydrogen-bonded base pairing, such as Watson-Crick base pairing and other non-canonical base pairs.

Statement D: Usually contains about \(65-100\) nucleotides.

This statement is false. RNA molecules can vary greatly in length. Some, like tRNA molecules, can be relatively short (approximately \(70-90\) nucleotides), whereas others, such as mRNA molecules, can be thousands of nucleotides long.

Statement E: Does not exhibit Watson-Crick base pairing.

This statement is false. RNA exhibits Watson-Crick base pairing, where adenine (A) pairs with uracil (U), and guanine (G) pairs with cytosine (C). However, RNA may also exhibit noncanonical base pairing, like G-U wobble pairs.