Question

Which of the following is the correct method to check whether the DNA has entered into the cell or not in the case of cosmid?

(a) If a transformation has taken place turbid plaques are formed

(b) If a transformation has taken place clear plaques are formed

(c) If a transformation has taken place, it can be confirmed via ampicillin resistance

(d) If a transformation has taken place, it can be confirmed if forms plaques and is ampicillin resistant also

I had been asked this question in quiz.

Question is from Lambda ZAP and Cosmids topic in portion Other Vector Systems for E of Genetic Engineering

Answer 1

The correct answer is (c) If a transformation has taken place, it can be confirmed via ampicillin resistance

To explain: In the case of cosmid, transformation can be confirmed via counting the colonies containing ampicillin. As the plaques are not formed by cosmids, it can’t be used as a method to detect transformation.