And inside that capsule we have a single stranded RNA molecule and it is given by 6390 nucleotides in length. So this is the length of that particular RNA molecule inside this virus. Now, once the tobacco mosaic virus actually infects that whole cell it injects the RNA molecule into that whole cell. And a special thing about this RNA molecule is it contains the genetic information that codes for a special protein known as RNA directed RNA polymerase. Now, remember, inside our bodies we take the DNA and we form the RNA molecule by using a special type of RNA polymerase. But inside these viruses this RNA polymerase actually transcribes RNA molecules from other RNA molecules and not DNA to RNA as it takes place inside our cells of the body.