Questions_Genome&HGT

Questions_Genome&HGT - QUESTIONS And ANSWERS for...

Info iconThis preview shows page 1. Sign up to view the full content.

View Full Document Right Arrow Icon
This is the end of the preview. Sign up to access the rest of the document.

Unformatted text preview: QUESTIONS And ANSWERS for the lecuture on The Bacterial Genome ad Horizontal Gene Transfer 1. List two features that insertion sequences and transposons have in common: 2. What is the one feature that distinguishes a transposon from and insertion sequence? 3. See the attached figure of an integron. This integron, prior to insertion of the IS element, conferred resistance to ampicillin, chloramphenicol, kanamycin, and neomycin. Now that that an IS element has inserted into the gene for chloramphenicol resistance, to what antibiotics do you predict this integron to confer resistance? (Choose all that apply) a. ampicillin b. chloramphenicol c. kanamycin d. neomycin e. none 4. You mix a Bacillus subtilis strain that is kanamycin resistance with a Staphylococcus epidermidis strain that is sensitive to kanamycin. After incubating these two cells together, you find that some of the S. epidermidis cells have become resistant to kanamycin. Choose the processes that you believe could explain how kanamycin resistance was transferred from B. subtilis to S. epidermidis. a. natural transformation b. phage transduction c. conjugation d. none of the above 4. You isolate cell-free culture supernatants from the growth of a kanamycin resistant strain of B. subtilis. You incubate a kanamycin-sensitive strain of S.epidermidis with the cell-free culture supernatant. After incubation, you find that some of the S. spidermidis cells have become kanamycin resistant. Choose the processes that you believe could explain how kanamycin resistance was transferred to S. epidermidis. a. natural transformation b. phage transduction c. conjugation d. none of the above 6. You treat the cell-free culture supernatants from the growth of a kanamycin resistant strain of B. subtilis with DNase. You then incubate the DNase-treated supernatants with a kanamycinsensitive strain of S.epidermidis. After incubation, you find that none of the S. spidermidis cells have become kanamycin resistant. Choose the processes that you believe could explain how kanamycin resistance was transferred to S. epidermidis in question number 5. a. natural transformation b. phage transduction c. conjugation d. none of the above 7. You have a purified preparation of a plasmid that can replicate in B. subtilis. This plasmid encodes chloramphenicol resistance. If you mix B. subtilis cells (lacking the plasmid) with the plasmid, and treat with an electrical current (i.e. electroporation or artificial transformation), some of the B. subtilis cells become resistant to chloramphenicol, indicating that these cells have acquired the plasmid. B. subtilis is naturally transformable. You isolate B. subtilis cells have have expresses genetic competence (i.e. naturally transformable cells). You incubate these genetically competent cells with the plasmid. After incubation, you find that none of the B. subtilis have become chloramphenicol resistant, indicating that the plasmid was not acquired. Explain why a plasmid could be acquired by artificial transformation but could NOT be acquired by natural transformation. ...
View Full Document

Ask a homework question - tutors are online