Question

RNA is the genetic material in
A) $T_2$ virus
B) $T_4$ virus
C) SV-400
D) TMV

Answer 1

RNA (ribonucleic acid) is an important biological macromolecule that is principally involved in the synthesis of protein.

Complete answer:
Viruses are small microscopic infectious agents that replicate inside the host’s cell. They can infect all types of life forms. They contain either DNA or RNA as the genetic material.
Let us analyze the options to find a correct option:
Option A: $T_2$ virus is a bacteriophage that infects E.coli. It has linear double-stranded DNA as its genome. Therefore this is an incorrect option.

Option B: $T_4$ virus is also a bacteriophage with double-stranded DNA as its genetic material. Therefore this is an incorrect option.

Option C: SV40 virus or Simian vacuolating 40 viruses is a DNA virus found in monkeys and humans and is responsible for causing tumors in animals. Therefore this is an incorrect option.

Option D: TMV (Tobacco Mosaic Virus) is the first virus to be discovered. It is one of the most stable viruses. This virus infects plants especially Tobacco and plants belonging to the family Solanaceae like cucumbers, tomato, pepper, etc. The infection causes ‘mosaic-like’ or irregular discoloration on the leaves. It contains positive-sense single-stranded RNA as its genetic material. Therefore this is the correct option.

Hence, the correct answer is option (D)

Note: 1. The main features of the virus are that they have the ability to mutate. They are acellular and have no cell organelles.
2. They do not carry out metabolism, instead, depend on the host’s cell metabolic machinery
3. They can reproduce only inside a host’s cell