Mtl,polA,and Xyl Are Bacterial Genes That Can Be Transmitted Using

Multiple Choice

mtl,polA,and xyl are bacterial genes that can be transmitted using an Hfr strain.An interrupted mating experiment resulted in xyl exconjugants appearing at 7 minutes and reaching maximum level by 30 minutes.The mtl gene function exconjugants appeared at 11 minutes and leveled off at 80% maximum by about 33 minutes,while polA did not appear until 24 minutes into the experiment and then only slowly rose to about 30%.Which of the following shows the gene order with the insertion site (arrow) location correctly?

A) xyl mtl polA →
B) polA mtl xyl →
C) mtl xyl polA →
D) mtl polA xyl →
E) None of these