You have isolated a newly discovered virus and are attempting to characterize it. You begin with its genome. You first isolate the virion-producing mRNA from cultured cells infected with the virus. When you compare this mRNA to the viral genome, you find that they are complementary. What does this tell you?
A) This virus has a positive-sense genome.
B) This virus has a negative-sense genome.
C) This virus has an ambisense genome.
D) The virus does not use DNA or RNA.

Question

Quizplus · Accepted Answer

The fact that the mRNA is complementary to the viral genome suggests that the mRNA is a negative-sense copy of the genome. This is because negative-sense RNA viruses (like influenza or Ebola) produce mRNA that is complementary to their viral genome. Positive-sense RNA viruses (like polio or Zika) have mRNA that is the same as their genome. Ambisense genomes have both positive-sense and negative-sense regions, and the mRNA would not be complementary to the whole genome. The fact that the virus has an mRNA indicates that it uses RNA as its genetic material.

You Have Isolated a Newly Discovered Virus and Are Attempting