One way to classify organisms is by analyzing their genetic information to determine where they belong within a phylogenetic tree or cladogram. Which of the following best describes a complication of classifying bacteria based on genetic information?

Question

elise_a18 · Answer

The DNA mutation rate of bacteria cannot be tracked, unlike other organisms.
 The DNA of bacteria is not made of the same nucleic acids as other organisms.
 The DNA in one species of bacteria can be exchanged with an unlike species of bacteria.
 The DNA of bacteria cannot be distinguished from the DNA of organisms they may use as a host.

elise_a18 · Answer

@aaronq

aaronq · Answer

Which ones can you absolutely rule out as possible answers?

nincompoop · Answer

think of vaccinations

somy · Answer

think of the shape and where the DNA of bacterium is located 
based on this we can distinguish bacteria from animal cell for example - knowing this, you can exclude some of the options 

now think of Griffith's experiment 
if you dont know about it, search and read  
after reading, think what kind of complication would it relate to? would it have effect on classification? if yes then what kind of problem would be there?