Question

1. The type of genetic exchange between bacterial cells that can happen between isolated DNA and a live bacterial cell is:

a. conjugation

b. transduction

c. transversion

d. transformation

2. An Hfr strain of E. coli with genotype a+b+c+d+e+f+ is mated with an F¯ auxotrophic strain with the genotype a¯b¯c¯d¯e¯f¯. Conjugation is stopped at 10 minute intervals and the genotypes of the resulting conjugants are determined. The following results are obtained:

after 10 minutes e+

after 20 minutes a+ e+

after 30 minutes a+ b+e+

after 40 minutes a+b+d+e+

after 50 minutes a+b+c+d+e+

after 60 minutes a+b+c+d+e+f+

Which represents the correct order of genes on this bacterial chromosomes?

1. efabcd
2. eabdcf
3. abcdef
4. fedcga
5. cdefab

3. A culture medium consisting solely of dextrose and inorganic salts would be considered a ____________ medium.

a. complete

b. differential

c. complex

d. minimal

e. selective

4. E. coli stains that are Hfr:

a. are susceptible to infection by bacteriophage.

b. are easily mutated.

c. cannot be made competent.

d. are highly recombinant.

5. The method used to visualize phage infection in bacteria is the:

a. the Hershey-Chase test

b. both A and C

c. Kirby-Bauer disk diffusion test

d. plaque assay

e. None of the above

6. A tryptophan auxotrophic strain (trp¯) of bacteria will be able to grow on a minimal medium agar that has been supplemented with the amino acid histidine.

a. true

b. false

7. Hfr strains result from the insertion and recombination of the F factor plasmid into the bacterial chromosome.

a. true

b. false

8. In generalized transduction, any gene or set of genes on the chromosome may be transferred from the donor bacterium to the recipient bacterium.

a. true

b. false

9. The order of genes on a bacterial chromosome can be determined by using transduction.

a. true

b. false

Answer 1

QUESTION 1

In this case, there are several mechanism that bacterial cells use to exchange DNA.

Transformation occurs between a bacterial cell and extracellular isolated DNA. On the other hand, transduction is between a bacteriophage (which contains the DNA) and a bacterial cell. Finally, a conjugation occurs between two bacterial cells. So, in this question, the correct answer is transformation

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