5. Genetics of Bacteria and Viruses
Bacterial Transformation
Back5. Genetics of Bacteria and Viruses
Bacterial Transformation
- Multiple Choice
Transformation is the process of what occurring with DNA?
- Multiple Choice
Scientists must use what type of cells to transform DNA in the laboratory?
- Multiple Choice
The DNA from a bacterium with the genotype a+ b+ c+ is used to transform a bacteria with the genotype a b c. Gene pairs were checked for cotransformation with the following results. Using these results determine which genes are linked.
- Open QuestionIn a transformation experiment, donor DNA was obtained from a prototroph bacterial strain (a⁺b⁺c⁺) and the recipient was a triple auxotroph (a⁻b⁻c⁻). What general conclusions can you draw about the linkage relationships among the three genes from the following transformant classes that were recovered?a⁺ b⁻ c⁻ 180a⁻ b⁺ c⁻ 150a⁺ b⁺ c⁻ 210a⁻ b⁻ c⁺ 179a⁺ b⁻ c⁺ 2a⁻ b⁺ c⁺ 1a⁺ b⁺ c⁺ 3
- Open QuestionDescribe the role of heteroduplex formation during transformation.
- Open Question
Penicillin was first used in the 1940s to treat gonorrhea infections produced by the bacterium Neisseria gonorrhoeae. In 1984, according to the CDC, fewer than 1% of gonorrhea infections were caused by penicillin-resistant N. gonorrhoeae. By 1990, more than 10% of cases were penicillin-resistant, and a few years later the level of resistance was at greater than 95%. Almost every year the CDC issues new treatment guidelines for gonorrhea that identify the recommended antibiotic drugs and dosages.
What are the long-term implications of these frequent changes in treatment recommendations for the patient population? - Open Question
Penicillin was first used in the 1940s to treat gonorrhea infections produced by the bacterium Neisseria gonorrhoeae. In 1984, according to the CDC, fewer than 1% of gonorrhea infections were caused by penicillin-resistant N. gonorrhoeae. By 1990, more than 10% of cases were penicillin-resistant, and a few years later the level of resistance was at greater than 95%. Almost every year the CDC issues new treatment guidelines for gonorrhea that identify the recommended antibiotic drugs and dosages.
What are the short-term implications of these frequent changes for physicians and clinics that treat sexually transmitted diseases like gonorrhea and for individuals infected with gonorrhea? - Open Question
Penicillin was first used in the 1940s to treat gonorrhea infections produced by the bacterium Neisseria gonorrhoeae. In 1984, according to the CDC, fewer than 1% of gonorrhea infections were caused by penicillin-resistant N. gonorrhoeae. By 1990, more than 10% of cases were penicillin-resistant, and a few years later the level of resistance was at greater than 95%. Almost every year the CDC issues new treatment guidelines for gonorrhea that identify the recommended antibiotic drugs and dosages.
Why is the CDC so active in making these recommendations? - Open QuestionIn Bacillus subtilis, linkage analysis of two mutant genes affecting the synthesis of two amino acids, tryptophan (trp₂⁻), and tyrosine (trp₁⁻), was performed using transformation. Examine the following data and draw all possible conclusions regarding linkage. What is the purpose of Part B of the experiment? [Reference: E. Nester, M. Schafer, and J. Lederberg (1963).]Donor DNA Recipient Cell Transformants No.trp⁺ tyr⁻ 196A. trp₂⁺ tyr₁⁺ trp₂⁻ tyr₁⁻ trp⁻ tyr⁺ 328trp⁺ tyr⁺ 367trp₂⁺ tyr₁⁻ trp⁺ tyr⁻ 190B. and trp₂⁻ tyr₁⁻ trp⁻ tyr⁺ 256trp₂⁻ tyr₁⁺ trp⁺ tyr⁺ 2
- Open Question
Define the term genetic complementation.
Locate another example of genetic complementation in this book and describe how genetic complementation works in that case. - Open QuestionIn a cotransformation experiment, using various combinations of genes two at a time, the following data were produced. Determine which genes are 'linked' to which others.Successful Cotransformation Unsuccessful Cotransformationa and d; b and c; a and b; a and c; a and f ;b and f d and b; d and c; d and f ;a and e; b and e; c and e;d and e; f and e
- Open QuestionFor the experiment in Problem 26, another gene, g, was studied. It demonstrated positive cotransformation when tested with gene f. Predict the results of testing gene g with genes a, b, c, d, and e.
- Open Question
A wild-type culture of haploid yeast is exposed to ethyl methanesulfonate (EMS). Yeast cells are plated on a complete medium, and 6 colonies (colonies numbered 1 to 6) are transferred to a new complete medium plate for further study. Four replica plates are made from the complete medium plate to plates containing minimal medium or minimal medium plus one amino acid4 (replica plates numbered 1 to 4) with the following results:
Identify the colonies that are auxotrophic (mutant). What growth information leads to your answer? - Open Question
A wild-type culture of haploid yeast is exposed to ethyl methanesulfonate (EMS). Yeast cells are plated on a complete medium, and 6 colonies (colonies numbered 1 to 6) are transferred to a new complete medium plate for further study. Four replica plates are made from the complete medium plate to plates containing minimal medium or minimal medium plus one amino acid4 (replica plates numbered 1 to 4) with the following results:
Identify the colonies that are prototrophic (wild type). What growth information leads to your answer?