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Title: A transformation experiment Post by: lawyerflaw on Dec 2, 2010 Suppose you have two strains that are trpB-. Call one of them trpB1- and the other trpB2-.
In one plate (plate #1) without tryptophan, combine trpB1- mutant cells with DNA from trpA- cells. In another plate (plate #2) without trptophan, combine trpB1- mutant cells with DNA from trpB2- cells. You notice that in Plate #1 with trpB1- and trpA- that there are colonies growing. How many colonies would you expect for Plate #2? a. there would be no colonies at all b. there would be some colonies, but less than the number in the experiment with trpA- DNA. c. there would be about the same number of colonies as the experiment with trpA- DNA. d. there would be many more colonies compared to the experiment with trpA- DNA. Title: Re: A transformation experiment Post by: bio_man on Dec 2, 2010 Your question lacks information. The answer I will give you is based on the assumption that trpB(1/2)- require tryptophan for growth. Consequently, I believe (a) there would be no colonies at all... is the answer.
Title: Re: A transformation experiment Post by: lawyerflaw on Dec 3, 2010 I have yet to find out what the correct answer is.
But that's the sorta questions we get for midterms and finals. :thi: Title: Re: A transformation experiment Post by: bio_man on Dec 3, 2010 Then you must have been told in class what they represent because whenever you have a negative beside a gene, then it indicates that the organism lacks the protein or enzyme. Since it says Trp, then the organism cannot produce the enzyme that either creates tryptophan or metabolizes it as a food source.
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