Which one contains double stranded RNA?
A. TMV
B. Reovirus
C. φ X 174
D. Cauliflower Mosaic Virus

Hint: It is a group of ribonucleic acid (RNA) viruses that make up the Reoviridae family, a diverse group of animal and plant viruses. All animal viruses containing multi-segmented dsRNA genomes are included in the Reoviridae family.

Complete answer:
- Ribonucleic acid or RNA is one of the three main biological macromolecules that are important for all recognised life forms along with DNA and proteins. RNA is single-stranded, unlike DNA. The RNA strand is made up of alternating sugar (ribose) and phosphate groups.

- RNA viruses have RNA as a genetic material and can be either a single-stranded RNA or a double-stranded RNA. Reovirus belongs to the group of ribonucleic acid viruses in the Reoviridae family. Reovirus is a highly soluble, double stranded RNA virus. It can cause asymptomatic, non-pathogenic or moderate gastroenteritis in humans.

- Cauliflower mosaic virus is a member of the Caulimoviridae family of spherical, double-stranded DNA viruses. It primarily infects members of the Brassicaceae family, like radish, turnip, canola, mustard, cauliflower, broccoli and cabbage. TMV is a single-stranded RNA virus. The virus spreads mechanically from contaminated plants to scratched or injured leaves of normal plants. Bacteriophage is a virus that destroys bacteria. The φ X 174 bacteriophage targets the normal human bacterium Escherichia coli, infecting the cell and causing it to develop new viruses. φ X 174 virus consists of a single DNA circle surrounded by a protein shell.

Thus, the correct answer is option B i.e., Reovirus.

Note: Reoviruses contain 10 fragments of dual-stranded RNA. While reoviruses are mostly non-pathogenic in humans, these viruses are very useful in laboratory models for viral pathogenesis studies.