1. A set of 4 Hfr bacterial strains were used in a time-of-entry experiment to map the locations of nine genes (A, B, C, D, E, F, G, H, I). The experiment was terminated after 22 minutes, which did not provide enough time to map all 9 genes with a single Hfr strain. Using the data on the amount of time it took to transfer each gene to a recipient during conjugation (see table below), draw a circular map of the genes on the bacterial chromosome. Your map should also indicate the Hfr origins of transfer with arrows. You don't need to indicate relative distances between genes, but you should use the given times of entry to figure out relative gene order. |G |H n/a 9 | BC D E F n/a n/a A I Hfr 1 n/a n/a 13 1 10| 13 n/a n/a | n/a | 14 n/a n/a 12 22 n/a n/a n/a n/a 2 | 8 18 n/a | 11 Hfr 2 17 n/a Hfr 3 4 6 n/a n/a Hfr 4 n/a | n/a | 2

1. A set of 4 Hfr bacterial strains were used in a time-of-entry experiment to map the locations of nine genes (A, B, C, D, E, F, G, H, I). The experiment was terminated after 22 minutes, which did not provide enough time to map all 9 genes with a single Hfr strain. Using the data on the amount of time it took to transfer each gene to a recipient during conjugation (see table below), draw a circular map of the genes on the bacterial chromosome. Your map should also indicate the Hfr origins of transfer with arrows. You don't need to indicate relative distances between genes, but you should use the given times of entry to figure out relative gene order. |G |H n/a 9 | BC D E F n/a n/a A I Hfr 1 n/a n/a 13 1 10| 13 n/a n/a | n/a | 14 n/a n/a 12 22 n/a n/a n/a n/a 2 | 8 18 n/a | 11 Hfr 2 17 n/a Hfr 3 4 6 n/a n/a Hfr 4 n/a | n/a | 2

Biology: The Dynamic Science (MindTap Course List)

4th Edition

ISBN:9781305389892

Author:Peter J. Russell, Paul E. Hertz, Beverly McMillan

Publisher:Peter J. Russell, Paul E. Hertz, Beverly McMillan

Chapter17: Bacterial And Viral Genetics

Section: Chapter Questions

Problem 1TYK

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You mix two auxotrophic strains of bacteria; one is leu+ trp+ his– met– and the other is leu– trp– his+ met+. After mixing the two strains, you plate the bacteria on minimal medium and observe a few prototrophic colonies (leu+ trp+ his+ met+). To determine whether gene transfer has occurred through conjugation, transformation, or transduction, you design an experiment in which you place filters between the two strains to see if gene transfer occurs. You set up three treatments:-Treatment A No filter, allowing contact between the bacterial strains-Treatment B Filter that blocks cells, but allows viruses and DNA through the filter-Treatment C Filter that blocks cells and viruses, but allows DNA through the filter When you check the results of your experiment, you find prototrophic colonies have occurred following treatments A and B, but not following treatment C. You conclude that gene transfer occurred through... Answer Choices Available: A) Conjugation B) Transformation C)…
A group of genetics students mix two auxotrophic strains of bacteria: one is leu+ trp+ his− met− and the other is leu− trp− his+ met+. After mixing the two strains, they plate the bacteria on minimal medium and observe a few prototrophic colonies (leu+ trp+ his+ met+). They assume that some gene transfer has taken place between the two strains. How can they determine whether the transfer of genes is due to conjugation, transduction, or transformation?
Q. The diagram is given below shows conjugation between F + or Hfr donor cells with F-recipient cells. On the basis of this diagram, answer the following questions.1. How you will differentiate between an F + and an Hfr strain? 2. Among two strains, which type of strain do you expect to transfer bacterial genes to F-cells? 3. What may be the end status of both donor and recipient cells of F plasmid-mediated conjugation? 4. What may be the end result when Hfr conjugates with F- cell?
All of the following apply to Luria and Delbrűck’s mutation theory as tested using E. Coli and T1 phage EXCEPT: A. It was performed using liquid bacterial cultures B. It involved looking for T1-resistant bacteria as an end measure C. It was supported by the finding that the number of final cultures that were T1 phage-resistant were constant from experiment to experiment D. It rejected the possibility of mutations occurring only in response to a T1 phage challenge E. It supported the concept of spontaneous mutation rates
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By conducting conjugation experiments between Hfr and recipientstrains, Wollman and Jacob mapped the order of many bacterialgenes. Throughout the course of their studies, they identified severaldifferent Hfr strains in which the F-factor DNA had been integratedat different places along the bacterial chromosome. A sample oftheir experimental results is shown in the following table: A. E xplain how these results are consistent with the idea that thebacterial chromosome is circular.B. Draw a map of the bacterial chromosome that shows the orderof genes and the locations of the origins of transfer among thesedifferent Hfr strains.
DNA from a strain of Bacillus subtilis with genotype a+ b+ c+ d+ e+ is used to transform a strain with genotype a– b– c– d– e–. Pairs of genes are checked for co-transformation and results shown below are obtained. Based on these results, what is the order of the genes on the bacterial chromosome? please show how you worked out the order by diagraming, thank you! Pair of genes Co-transformation a+ and b+ no a+ and c+ no a+ and d+ yes a+ and e+ yes b+ and c+ yes b+ and d+ no b+ and e+ no c+ and d+ no c+ and e+ yes d+ and e+ no
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A patient has a Haemophilus influenzae respiratory infection. She is prescribed Amoxicillin. Unfortunately, this strain of H. influenzae has resistance to this antibiotic. Her symptoms worsen. When she again visits the doctor, a nasty Amoxicillin resistant Streptococcus is isolated from her nasal passages. What is the most likely explanation? transduction. conjugation. transformation. none of the above
Austin Taylor and Edward Adelberg isolated some new strains of Hfr cells that they then used to map several genes in Escherichia coli by using interrupted conjugation. In one experiment, the researchers mixed cells of Hfr strain AB‑312, which were xyl+ mtl+ mal+ met+ and sensitive to phage T6, with F− strain AB‑531, which was xyl− mtl− mal− met− and resistant to phage T6. The cells were allowed to undergo conjugation. At regular intervals, the researchers removed a sample of cells and interrupted conjugation by killing the Hfr cells with phage T6. The F− cells, which were resistant to phage T6, survived and were then tested for the presence of genes transferred from the Hfr strain. The results of this experiment are shown in the graph. On the basis of these data, give the order of the xyl, mtl, mal, and met genes on the bacterial chromosome and the minimum distances between them in minutes. The origin of transfer is represented by the red triangle. The distances between genes are not…
Austin Taylor and Edward Adelberg isolated some new strains of Hfr cells that they then used to map several genes in E. coli by using interrupted conjugation . In one experiment, they mixed cells of Hfr strain AB-312, which were xyl+ mtl+ mal+ met+ and sensitive to phage T6, with F− strain AB-531, which was xyl− mtl− mal− met− and resistant to phage T6. The cells were allowed to undergo conjugation. At regular intervals, the researchers removed a sample of cells and interrupted conjugation by killing the Hfr cells with phage T6. The F− cells, which were resistant to phage T6, survivedand were then tested for the presence of genes transferred from the Hfr strain. The results of this experiment are shown in the accompanying graph. On the basis of these data, give the order of the xyl, mtl, mal, and met genes on the bacterial chromosome and indicate the minimum distances between them.
In a P1 transduction experiment, the P1 lysate contains phages thatcarry pieces of the host chromosomal DNA, but the lysate also containsbroken pieces of chromosomal DNA. If a P1 lysate is used to transfer chromosomal DNA to another bacterium, how could you show experimentally that the recombinant bacterium has been transduced (i.e., has taken up a P1 phage with a piece of chromosomal DNA inside) versus transformed (i.e., has taken up a piece of chromosomal DNA that is not within a P1 phage coat)?