Question

Read the following statements. Which of the following statements about RNA molecule is incorrect?
$I.$ It has a double-helical structure.
$II.$ It contains ribose which is a cyclic aldopentose monosaccharide.
$III.$ It is the genetic material in all animal viruses.
$IV.$ It contains ribothymidylic acid.

• A. I, III and IV only
• B. III and IV only
• C. I and II only
• D. I, II, III and IV

Answer 1

Answer: (A)

Ribonucleic Acid is a single stranded molecule which may show folding onto itself than forming a paired double strand like DNA. It does not form a helical structure. The nucleotide of RNA has a sugar molecule $-5C-$ pentose ribose with aldehyde as the functional group (aldose monosaccharide), a phosphate attached to the sugar and lastly, a nitrogenous base which is either adenine, guanine, uracil or cytosine. Uracil is replaced by thymine in DNA. Some animal viruses have DNA as the genetic material e.g. Hepatitis B virus while some animals have RNA as the genetic material e.g. HIV. Statement I, III and IV are incorrect regarding RNA and only statement II is correct.