During a recombinant DNA experiment, a student digests a circular plasmid vector with a specific restriction endonuclease. Upon running the digested sample on an agarose gel, the student observes four distinct DNA bands instead of a single band. Which desirable feature of an ideal cloning vector did this plasmid lack with respect to the chosen enzyme?

Step-by-step solution

When a circular plasmid is digested by a restriction enzyme and run on an agarose gel, the number of DNA bands observed corresponds to the number of recognition sites for that enzyme on the plasmid. Observing four distinct bands indicates that the restriction enzyme cut the plasmid at four different locations, generating four separate fragments. An ideal cloning vector should have very few, preferably single, recognition sites for a given restriction enzyme. If multiple sites are present, the vector is broken into