USA Biology Olympiad (USABO) Practice Exam

If RNA from a tobacco mosaic virus is combined with proteins from a human rhinovirus, what type of virus would result if it could reproduce?

1. Human Rhinovirus

2. Tobacco Mosaic Virus

3. Mixed Virus with human and tobacco characteristics

4. Both viruses would neutralize each other

The correct answer is: Tobacco Mosaic Virus

When RNA from the tobacco mosaic virus (TMV) is combined with proteins from the human rhinovirus (HRV), the resulting virus would exhibit the characteristics of the tobacco mosaic virus, provided it can reproduce. This is because viruses are highly specific about their genetic material and structure. The RNA of the TMV carries the information needed to produce viral proteins specific to TMV, and the protein structures of TMV dictate how the virus interacts with host cells, including plant cells, which is essential for its replication. Human rhinovirus, on the other hand, has a completely different RNA and protein structure optimized for infecting human cells and replicating within them. Since the RNA of the TMV is dominant in this scenario, it will ultimately dictate the characteristics of any new infectious particles formed, leading to the formation of TMV particles rather than any hybrid or new set of characteristics from HRV. In this scenario, the possibilities of forming a mixed virus with characteristics from both or them neutralizing each other are not supported by the fundamental principles of virology. Therefore, the result would indeed be the Tobacco Mosaic Virus, as it is the genetic material that primarily governs the nature of the virus.