Chapter 12.2, Problem 1TC

Some viruses, such as the tobacco mosaic virus (TMV), consist of a protein coat surrounding ribonucleic acid (RNA) instead of DMA. A few years after the Hershey-Chase experiments, Heinz Fraenkel-Conrat and several colleagues separated TMV of two different strains (normal and HR) into their protein and RNA components. They then mixed the protein from strain HR with RNA from the normal strain, and vice versa. Hybrid viruses (either HR protein coats with normal RNA or normal protein coats with HR RNA) spontaneously assembled in these mixtures. They then allowed the hybrid viruses to infect tobacco plants and produce new viruses. If RNA is the genetic material of TMV, predict the type of protein coats formed by the offspring of hybrid viruses.