Bacteria have obtained the $\beta$-lactamase gene which encodes a protein that renders all $\beta$-lactem antibodies such as ampicillin and penicillin inactive.Which of the following would result in an increased number of bacteria with this ability?
(I)a transposon with the $\beta$-lactamase gene
(II)a recombination event within the original strain that results in a point mutation inactivating $\beta$-lactamase
(III)an insertion in the original strain rendering transposase inactive
(IV)a deletion in the insertion sequence of the transposon

Question

Quizplus · Accepted Answer

Only the presence of the F1F1F1S1F1F1F10-lactamase gene on a transposon directly contributes to the bacteria's ability to render F1F1F1S1F1F1F10-lactem antibiotics inactive. Recombination resulting in a point mutation inactivating the gene or deletions in an insertion sequence do not contribute to the bacteria's ability to produce the lactamase. An insertion rendering the transposase inactive would prevent the transposon with the lactamase gene from moving to other bacteria, but it wouldn't increase the number of bacteria with the lactamase gene. Therefore, choice B (I only) is the correct answer.

Bacteria Have Obtained The β\betaβ -Lactamase Gene Which Encodes a Protein That Renders All

Bacteria Have Obtained The $\beta$ -Lactamase Gene Which Encodes a Protein That Renders All