We have two specific strains of E. coli that have shown horizontal gene transfer (HGT) when mixed. To experimentally determine the method of HGT that is happening, the following conditions are set up in different tubes of culture media: A) Donor and recipient strain mixed together (control - no treatment). B) Donor and recipient strains mixed together, DNase added (can digest DNA in solution, not within cells). C) Special tube containing a membrane filter (with pores that allow DNA and viruses to pass through, but not bacterial cells) that separates two compartments. Donor strain is added on one side, the recipient strain on the other (they are separated by the filter). D) Donor and recipient strains mixed together, with chemical that inactivates viruses (chemical affects bacteriophages in solution so they are unable to attach to cells).
The results:
Tubes A, C, and D: HGT was observed. Tube B: HGT was NOT observed. Based on this, which type of HGT was occurring?
Conjugation, transduction or transformation.
Transformation.
Transduction.
Conjugation.