The question seem to be incomplete but I found the complete question which is:
If you are performing this test on an unknown organism, why is it a good idea to run simultaneous tests on known phenylalanine-positive and phenylalanine-negative organisms?
Here is the Answer:
Inoculation of a positive control and success from it includes certainty to negative outcomes on an unknown organism. That is, you know the test is working effectively, so the negative outcome is most likely precise. Without the positive control, there is dependably a component of uncertainty whether the negative outcome is a genuine negative or a false negative. performing the test on a known phenlalanine-negative organism is valuable in that it exhibits what a negative outcome looks like.
Answer:
for differentiation
Explanation:
By gram staining, we can determine about gram-positive and gram-negative bacteria. If bacteria are Gram-positive then for further catalase test perform. If bacteria give catalase-positive then that's mean this bacteria is Staphylococcus. If bacteria give catalase-negative result then that's mean this bacteria is streptococcus.
The bacteria that are catalase-positive for their further identification coagulase test perform if bacteria is coagulase-positive that's mean it is staphylococcus aureus and if it is coagulase-negative that's mean that maybe differentiation saprophyticus or other species.
<span>Summer temperatures in the Arctic remain cool, fluttering around zero in many places, from June through September. In fact, Arctic residents must frequently heat their homes all year long. Neighbourhoods near the sea tend to remain close to 0°C throughout the summer, but inland areas, particularly in the south, regularly reach 7°C–13°C, and hardly as much as 20°C. One reason for the opposition is that the sea ice, which gradually melts, consumes much of the sun's energy, giving little to heat the air over it.
Hope this helped! :)</span>
Answer:
schistosomiasis
Explanation:
Helminths are the parasites with a worm-like body structure and include the flatworms, tapeworms, and nematodes.
Trematode flatworms are the flatworms that cause the disease schistosomiasis. The schistosomiasis parasite is spread when freshwater snail releases its larva in the water bodies which in turn enter the healthy person bathing in the water.
We know that Hardy-Weinberg conditions include the following equations:

where 
And where p = dominant, and q = recessive; this means that
is equal to the homozygous dominant,
is the heterozygous, and
is the homozygous recessive .
So we have 100 total cats, with 4 having the recessive white coat color. That means we have a ratio of
or 0.04. Let that equal our
value.
So when we solve for q, we get:


Now that we have our q value, we can use the other equation to find p:



So then we can solve for our heterozygous population:

This is the ratio of the population. So we then multiply this number by 100 to get the number of cats that are heterozygous:

So now we know that there are 32 heterozygous cats in the population.