Question 1-As you have learned viruses must be able to package their genomes within a small capsid. The picture below is an atomic detail model of an icosohedral (+) strand RNA virus with a diameter of 30 nm. Most models of viruses show the genome as small “squiggly” lines, but this model demonstrates how the genome is tightly packed within the capsid. Assuming that the virus capsid is spherical, work with your classmates to calculate what is the maximum genome size (in nucleotides) that can fit into the capsid. How long in millimeters would this largest possible RNA genome be?
Question 2-The largest known virus was reported this past summer. It is so large it can be viewed with a light microscope and has a genome size of 2.45 mega bases, which is larger than many bacteria. One of the pictures below is of this new virus inside a host amoeba, while the other is a picture of a similar sized intracellular bacterium infecting a host eukaryotic cell. Given what you learned last week on the different methods for assaying/characterizing viruses as well as the differences between viruses and cells; propose experiments you could perform to determine whether the pictured entities are viruses or bacteria.
