(Solved): 1. You are using the pUC18 vector to construct a genomic DNA clone using yeast DNA. You have cut th ...

1. You are using the pUC18 vector to construct a genomic DNA clone using yeast DNA. You have cut the ycast DNA and the pUC18 vector with restrietion enzyme BamHI, purified the digested DNA to remove all restriction enzymes, mixed the DNAs together in a ligation reaction, and then transformed a lacZ: strain of $E$ coll. You plated the same number of transformants on three different petri plates containing medium made at three different times by different technicians during the previous weck. Plate 1 contains 1000 colonies. About 500 of the colonies are blue, and the other half are white. Plate 2 contains about a million colonies, and almost all of them are white. Plate 3 contains about 1000 colonies, and all of them are white. You suspect that plate 1 contains medium that was properly prepared, and that plates 2 and 3 are each missing a different component. pUC18 has a multipla cloning site within the lac $Z$ alphafragment inserts cloned into this site disrupt beta -galactosidase (tacZ) activity and give rise to white colonies on X.GahPTG plates. The plasmd encode resistance to the antibiotic ampicillin. a. What important components did plate I contain that allowed selection of the plasmid and screcning for the presence of plasmid inserts? b. What seems to bo missing from plate 2 ? c. What seems to be missing from plate 3 ?