In the Osmotic Pressure lab, the results are based upon turbidity measurements.
ID: 90697 • Letter: I
Question
In the Osmotic Pressure lab, the results are based upon turbidity measurements. A relatively low turbidity suggests:
Select one:
a. More bacterial growth
b. The culture will be relatively cloudy
c. A color chang occured
d. Less bacterial growth
If the Staphylococcus aureus grew more in a 5% NaCl environment than it did in 2% or 11% NaCl, you would conclude that it is probably a:
Select one:
a. Extreme halophile
b. Osmotolerant
c. Intestinal bacteria
d. Halophile
False negatives are likely in a test with low:
Select one:
a. Sensitivity
b. Specificity
c. Experimental variables
d. 10% bleach solution
e. Sharps container
An experimental result that is positive when the microbe of interest was present is a:
Select one:
a. A false negative
b. A false positive
c. A true negative
d. A true positive
e. Low sensitivity
Explanation / Answer
Turbidity would be casued by large particles suspended in a liquid not allowing light to pass through thus causing cloudiness of the fluid. A relatively low turbidity suggests low bacterial growth.
answer is d.
Staphylococcus grows in a wide variety of environments with varying osmotic pressure and so is called osmotolerant.
Answer is b
False negatives are likely in a test with low sensitivity. If the test performed will be positive for an orgnaism but under certain conditions it may be negative , then this test result will come up as false negative.
Answer is a.
An experimental result that is positive when the microbe of interest was present is a A true positve. The reason is as the experiment was performed targeted to the microbe of interest, it will show whether the microbe of interest is present or not and in this case it states positive and therefore the answer is a true positive out of all the provided options.
Answer is d