Question 45

[matthew]

Dr. Ferdinand,

Why can't B be correct. During the exam I notices that all plates did not have 0% killed bacteria. Then I thought about bacteria having plasmids and having antiobiotic resistance.

Wouldn't the varying ratios of resistance prove that all the bacteria have some form of anti-resistance genes?

[admin]

Your logic regarding resistance if fine. The key word in B and your conclusion is "all." Some bacteria were easily killed by both antibiotics. The conclusion must be that some bacteria are sensitive to the antibiotics. Thus all the bacteria cannot be resistant otherwise the survival would be around 100% in all plates.

[mvenus9292913]

What about C? We know some died using Antibiotic B, and a lot died using antibiotic A, so why wouldn't a combination of the two result in the greatest number dying?

[admin]

This question is in the "best answer" category.

The difference between C and D is essentially comes down to the following question: which case would you find the highest bacteria killed?

C) using antibiotic B after the bacteria were already treated with A

D) using antibiotic A after the bacteria were already treated with B

D is the best answer.

[admin]

bump