Swimmer

1. A bacterial cell does not have a gene encoding a multi-drug efflux pump. The cell is sensitive to antibiotics. It takes up a linear fragment of DNA from the environment, which has a gene encoding a multi-drug efflux pump.

a. DNA uptake from the environment is Transformation

b. Will the cell become antibioticR? Why or why not?

No, the cell stays sensitive to antibiotics because there is no homologous efflux pump.

2. A bacterial cell does not have a gene encoding a multi-drug efflux pump. The cell is sensitive to antibiotics. It takes up plasmid from the environment, which has a gene encoding a multi-drug efflux pump.

a. Will the cell become antibioticR? Why or why not?

Yes, the cell will become resistant to antibiotic because of the plasmid punp.

3. A bacterial cell has a mutated (& in this case non-functional) version of a gene encoding a multi-drug efflux pump. The cell is sensitive to antibiotics. It takes up a linear fragment of DNA from the environment, which has a gene encoding a multi-drug efflux pump.

a. Will the cell become antibioticR? Why or why not?

Yes, the cell will become resistant to the antibiotic because of the mutated DNA version of the gene that will be replaced by the one from the environment and then recombined.

b. Would your answer change if I told you that the cell also had a mutation in the gene encoding one of the key rec genes? Why or why not?

No, because rec genes are not functional.

4. A self-transmissible plasmid encodes a multi-drug efflux pump. The plasmid is transferred from a donor cell in direct physical contact with a recipient cell, which was initially antibioticS.

a. DNA transfer directly from a donor to a recipient is conjugation.

b. Will the recipient cell become antibioticR? Yes.

c. What about if the plasmid had a deletion of its OriT? No.

d. What about if the plasmid had a frameshift mutation in one the key RTF genes, encoding a key tra protein? No.