You transformed a strain of E. coli with a plasmid containing a transposon that includes an ampicillin-resistance gene. To recover the plasmid, you pick a colony from a culture plate containing ampicillin. Much to your surprise, the plasmid you recover is twice the size you expected. You then pick 100 more colonies and discover that only one of them has plasmid of the expected size.
(a) Why is the recovery of plasmid of expected size so low?
(b) Why can you recover any plasmid of expected size at all?