It contains the five prime cap and the polyatail on the three prime N and it only contains the exons, it does not contain the introns. Now, before we can actually add reverse transcriptase into the mixture, we have to create a DNA primer and we have to attach that DNA primer onto the three prime end of that mRNA molecule. Now, because all mRNA molecules in eukaryotic cells are modified with a polyatail, what that means is it's pretty easy to produce that DNA primer that is complementary to the polyatail. Because all we have to do is create a polyceetail. Because we know if we have the A's on this side, they will base pair with the T's on the other side. So we basically create a DNA primer complementary to the three end of the modified mRNA molecule and recall that all eukaryotic mRNA have a polyatail on the three prime ends.