Concept explainers
For bacteria that are
a. Describe the state of the F factor.
b. Which of these cells are donors? Which is the recipient?
c. Which of these donors can convert exconjugants to a donor state?
d. Which of these donors can transfer a donor gene to exconjugants?
e. Describe the results of conjugation (i.e., changes in the recipient and the exconjugant) that allow detection of the state of the F factor in a donor strain.
f. Describe a “partial diploid” and how it originates.
To review:
For bacterial strains
Description for the state of the F factor.
Identification and explanation of donor and recipient cells.
Identification and explanation of donor cells that can convert exoconjugants to donor state.
Identification of the donor that can transfer the donor gene to exoconjugants.
Description of results of conjugation that allow detection of the state of the F factor in the donor strain.
Description on partial diploids.
Introduction:
Conjugation is the process of transfer of the DNA from one donor bacterium to a recipient bacterium. It is also known as lateral gene transfer. Conjugation is always occurring between the donor cell and the recipient cell, it does not occur between two donor cells. The exoconjugant cell is the recipient cell that has a modification in their genome by receiving the DNA from a donor cell in the process of conjugation. During conjugation, bacteria come in contact with the help of sex pilus. The bacterium that has sex pilus is the donor - male bacterium, and the bacterium that lacks sex pilus is the recipient - female bacterium.
The cell that has the ability to donate their DNA is called
Explanation of Solution
The
Hfr (high frequency recombination)
Donor cell is a cell that donates factor/s to another cell by conjugation. Only that bacterial cell which already has the
The
Hfr and
At the time of conjugation, bacterium comes in contact with the help of sex pilus. The bacterium that has sex pilus is the donor - male bacterium, and the bacterium that lacks sex pilus is the recipient - female bacterium. Conjugation tube is formed between the donor and recipient, and F sex factor is transferred from
A bacterium that has two copies of some of its genes (not all) is termed as partially diploid. In a bacterium, one copy of the desired gene is present on the bacterial genome, and another copy may be fused with the plasmid. Now, the bacterial cell possesses one complete set of genes and identical copy of portion of the genome.
Example of formation of partial diploid:
Conclusions:
The bacterium that has plasmid is
The
Hfr and
A bacterium that has two copies of some of its genes (not all) is termed as partially diploid.
Want to see more full solutions like this?
Chapter 6 Solutions
GENETIC ANALYSIS: INTEGRATED - ACCESS
- . a. You want to perform an interrupted-mating mappingwith an E. coli Hfr strain that is Pyr+, Met+, Xyl+,Tyr+, Arg+, His+, Mal+, and Strs. Describe anappropriate bacterial strain to be used as theother partner in this mating.b. In an Hfr × F− cross, the pyrE gene enters therecipient in 5 minutes, but at this time point thereare no exconjugants that are Met+, Xyl+, Tyr+,Arg+, His+, or Mal+. The mating is now allowed toproceed for 30 minutes and Pyr+ exconjugants areselected. Of the Pyr+ cells, 32% are Met+, 94% areXyl+, 7% are Tyr+, 59% are Arg+, 0% are His+, and71% are Mal+. What can you conclude about theorder of the genes?arrow_forwardIn the Avery, McLeod, McCarty Experiment where supernatant from heat killed, virulent S Strain pneumonia solutions were added to non-virulent R Strain pneumonia cell cultures and allowed to grow in liquid media (i.e., broth). In tubes where Protease was added to the supernatant prior to cell culture, what was the observed effect when plating and growing the S. pneumonia cells to solid media? Selected answer will be automatically saved. For keyboard navigation, press up/down arrow keys to select an answer. a b C d e All RNA was degraded and Transformation of the R Strain to S Strain occurred. All Protein was degraded and Transformation of the R Strain to S Strain occurred. All DNA was degraded and Transformation of the R Strain to S Strain occurred. All RNA was degraded and no Transformation occurred indicating RNA is the molecule of Transformation inheritance None of the above are truearrow_forwardIn a process of production of a recombinant protein by E. coli cells, it was observed accumulation of acetate in the culture medium. In this situation, it can be said that: (a) certainly the process in question was being conducted in anaerobiosis (B).Acetate accumulation is advantageous for the process as the acetate formation reaction generates 1 molecule of ATP (c)Knowing that decreasing the temperature of the process causes a reduction in the rate of glycolysis, this could be a strategy to reduce the accumulation of acetate (d).the acetate formed can be re-assimilated by the cell if the glyoxylate pathway is activated at some point in the culturearrow_forward
- Various antimicrobial drugs to treat microbial infection have diverse mechanism of action. Consider the following antimicrobial drugs: A. Seconeolitsine, known as DNA topoisomerase I inhibitor in bacteria. (i) Explain briefly how inhibiting DNA topoisomerase I is a good mechanism of action for an antibiotic, include possible molecular machineries being targeted. (ii) What would be an appropriate response if seconeolitsine works well by stating the state of supercoiling in bacteria. (iii) To prove your answer (ii), you test the condition of bacterial DNA by running gel electrophoresis, one has been treated with seconeolitsine (+ sample) and the other one is not (- sample). Explain the position of each + sample and – sample band on the gel in reference to the point of origin (where you load your samples) or how far each DNA sample travel across agarose gel. (iv) Explain why you would expect answer (iii) for each + sample and – sample. B.…arrow_forwardIn the Meselson experiment, would it have been possible to utilize N14 in the original bacteria and only allow growing bacteria to access N15 to build new (F1) bacteria and get the same results? Explain why. (I need an answer in full complete sentences with the question restated in the response.)arrow_forwardA prototrophic strain (his" arg" lac') was used as a donor to transform an auxotrophic strain (his arg lac'). Initial transformants are isolated on minimal medium + histidine + arginine + lactose - glucose. i. What genotypes will grow on this medium? ii. These colonies are replicated to minimal medium + histidine, and 50% of the original colonies grow. What genotypes will grow on this medium? iii. The original colonies are also replicated to minimal medium + arginine, and 10% of the colonies grow. What genotypes will grow on this medium? iv. The original colonies are also replicated to minimal medium. No colonies grow. Based on this information, what genotypes will grow on minimal medium + histidine and on minimal medium + arginine? What is the relative gene order for his, arg, and lac? Which two genes are closer? Explain your answer.arrow_forward
- You are a bacteriologist studying a pathogenic protein (the “BAD” protein) that contributes to diseases caused by Staphylococcus aureus. BAD functions as an ab heterodimer, and the a subunit (25kD) and b subunit (75kD) are held together by an electrostatic interaction between K in the a subunit and D in the b subunit. You are trying to dissociate the BAD subunits to prevent pathogenesis in the bacteria. Which mutation would you make to prevent the BAD subunits from forming a dimer? Assume neutral pH. (A) introduce AAA to AGA point mutation in the a subunit gene(B) introduce GAC to GAG point mutation in the b subunit gene(C) introduce GAT to CGT point mutation in the b subunit gene(D) introduce two point mutations: AAG to GTG in the a subunit gene & GAC to CTC in the b subunit gene (E) introduce two point mutations: AAA to TGC in the a subunit gene & GAT to TGT in the b subunit genearrow_forwardTo understand the genes responsible for growth and infectivity in a disease-causing bacterial strain, you perform chemical mutagenesis on a culture of these bacteria. In the course of your investigation into the properties of the resulting mutants, you identify a set of mutant bacteria that is still viable but their virulence is significantly impaired. How might these mutants be useful for vaccine development?arrow_forwardGiven what we've discussed in class, what will be most likely outcome if you conjugate an streptomycin resistant ampicillin sensitive methionine auxotroph E. coli strain (engineered to be pir+) that is F- with a streptomycin sensitive non-HFR methionine prototroph strain that is F- and RP4+ but contains pUC18? Colonies on minimal media + ampicillin +streptomycin plates No colonies on minimal media +ampicillin +streptomycin platesarrow_forward
- A plaque assay is performed beginning with 1 mL of a solution containing bacteriophages. This solution is serially diluted 3 times by combining 0.1 mL of each sequential dilution with 9.9 mL of liquid medium. Then 0.1 mL of the final dilution is plated in the plaque assay and yields 12 plaques.What is the initial density of bacteriophages in the original 1 mL? Enter your answer to two significant figures ( for example: 1.1 * 10^2)arrow_forwardIn a generalized-transduction experiment, phages arecollected from an E. coli donor strain of genotype cys+leu+ thr+ and used to transduce a recipient of genotypecys- leu- thr-. Initially, the treated recipient populationis plated on a minimal medium supplemented with leucine and threonine. Many colonies are obtained.a. What are the possible genotypes of these colonies?b. These colonies are then replica plated onto threedifferent media: (1) minimal plus threonine only, (2)minimal plus leucine only, and (3) minimal. Whatgenotypes could, in theory, grow on these three media?c. Of the original colonies, 56 percent are observed togrow on medium 1, 5 percent on medium 2, and nocolonies on medium 3. What are the actual genotypes ofthe colonies on media 1, 2, and 3?d. Draw a map showing the order of the three genes andwhich of the two outer genes is closer to the middle genearrow_forwardAmong the following statements regarding the use of viral vectors, which is (are) true: (can be more then one answer) A.Viral vector transfection has the defect of rapidly killing cells, given the high toxic potential of viruses. B.Generally, the effectiveness of a viral infection transfection is much higher than an electroporation or cationic liposome transfection. C.Even before infecting a cell, a virus can begin to express the indicators, accelerating the process of expression of the indicator in the culture medium. D.Adeno-associated viruses are little used in biophotonics, as they require simultaneous adenovirus infection.arrow_forward
- Human Anatomy & Physiology (11th Edition)BiologyISBN:9780134580999Author:Elaine N. Marieb, Katja N. HoehnPublisher:PEARSONBiology 2eBiologyISBN:9781947172517Author:Matthew Douglas, Jung Choi, Mary Ann ClarkPublisher:OpenStaxAnatomy & PhysiologyBiologyISBN:9781259398629Author:McKinley, Michael P., O'loughlin, Valerie Dean, Bidle, Theresa StouterPublisher:Mcgraw Hill Education,
- Molecular Biology of the Cell (Sixth Edition)BiologyISBN:9780815344322Author:Bruce Alberts, Alexander D. Johnson, Julian Lewis, David Morgan, Martin Raff, Keith Roberts, Peter WalterPublisher:W. W. Norton & CompanyLaboratory Manual For Human Anatomy & PhysiologyBiologyISBN:9781260159363Author:Martin, Terry R., Prentice-craver, CynthiaPublisher:McGraw-Hill Publishing Co.Inquiry Into Life (16th Edition)BiologyISBN:9781260231700Author:Sylvia S. Mader, Michael WindelspechtPublisher:McGraw Hill Education