Problem:
In constructing the molecular phylogeny, researchers extracted DNA from Vibrio cholerae and then compared housekeeping gene sequence homology in order to characterize the sample strains.
Which of the following statements summarizes why housekeeping genes can be used in multilocus sequence typing (MLST)? Please choose the best answer:
Housekeeping genes are easily exchanged between species.
Housekeeping genes are always encoded on plasmids that can be easily extracted.
Housekeeping genes are not easily exchanged across strains.
Housekeeping genes are not likely to be under environmental selection.
Housekeeping genes evolve with time based on the location of the bacterium.