One advantage of using two restriction enzymes to cut a plasmid is that it increases the chances of obtaining the desired recombinant DNA. Restriction enzymes recognize specific sequences of DNA and cut at those specific points. By using two different enzymes, you can create two distinct cuts in the plasmid, which will increase the chances of obtaining the desired recombinant DNA. Additionally, two restriction enzymes can be used to get higher yields of the recombinant DNA, as the number of cuts increases the amount of DNA that can be obtained.

What happens if you cut 2 different sources of DNA with the same restriction enzyme?

If you cut two different sources of DNA with the same restriction enzyme, they will both be cut into the same size fragments. This is because restriction enzymes recognize specific sequences in DNA and cut the DNA at those sequences, regardless of the source of the DNA. However, the exact size of the fragments will depend on the exact sequences recognized by the restriction enzyme.

Why does using two different enzymes to cut the plasmid prevent the plasmid from reforming a circle?

Using two different enzymes to cut the plasmid prevents the plasmid from reforming a circle because the two enzymes cut the plasmid at different locations. The two cuts create staggered ends which are difficult to align correctly and therefore prevent the plasmid from reforming into a circle. The staggered ends also prevent the plasmid from being recircularized when it is put into a cell.