pBR322 DNA (4.36 kb; see Figure 4A.3) was cleaved with Hind III nuclease and ligated to a

Question:

pBR322 DNA (4.36 kb; see Figure 4A.3) was cleaved with Hind III nuclease and ligated to a Hind III digest of human mitochondrial DNA. One recombinant plasmid DNA was analyzed by gel electrophoresis of restriction cleavage fragments, with the following results: lane A = Eco RI-treated recombinant, lane B = Hind III-treated vector, and lane C = Hind III-treated recombinant.

(a) Why was the recombinant plasmid treated with Eco RI to determine its size?
(b) How might you explain the discrepancy between the size of the recombinant molecule and the sum of the sizes of the Hind III cleavage fragments?
(c) Draw a diagram of the recombinant showing the locations of the Hind III cleavage sites.