Question

A microbiologist is attempting to determine the size of a microbial population and has employed several methods. She noticed that the direct count she obtained using a counting chamber and microscope was much higher than her estimate from doing a viable plate count. This discrepancy was encountered during multiple trials. What is the most likely reason for the discrepancy?A. she counted incorrectly
B. she did not correctly do the serial dilutions prior to the viable plate count
C. many of the organisms viewed during the direct count may be dead
D. the medium and growth conditions used for the viable count will not support the growth of the organisms
E. more than one of the above but not all of the above

Answer 1

Answer:

The answer is E.

Explanation:

For the given example where the microbiologist is doing the microbial population count first with a viable plate count which is a method that does not require a microscope, then with using a counting chamber using a microscope which results in a higher count than the first method.

The reason for that can be that her first viable plate count was incorrect, she did not do the serial dilutions before doing the viable plate count which would affect the microbial population density. The options C and D are not applicable to this example.

So the answer is more than one of the above but not all of the above which is E.

I hope this answer helps.