When crossing a true breeding white mouse with a true breeding brown mouse your friend tells you she recovered all black mice. But then when she crosses the F1 mice to each other she recovered 28 black mice, 8 brown mice, and 13 white mice. Can you help her explain these results? (Type out the cross and include genotypes of as many mice as possible. What phrase best describes this phenomenon? How many genes are involved are they linked or unlinked? Etc.)

Following are the response to the given question:  

Explanation:

The observed progeny ratios closely match the morphological ratio of 9:3:4. That's a hereditary pharmacogenetic example.

Applying a number of distinct genes = 2

You have really no connection

Phenomenon=Recessive Epistasis

answer; i believe that the correct answer is ; males are hemizygous for the x chromosome;

hypoxemia refers to a below usual concentration of oxygen in the blood, mainly in the arteries. hypoxemia is an indication of an issue associated with circulation or breathing and may lead to various symptoms like shortness of breath.  

the condition is identified by determining the level of oxygen in the blood sample obtained from an artery. it can also be predicted by determining the oxygen saturation of the blood with the application of a pulse oximeter.  

the normal arterial oxygen is about 75 to 100 mm hg. the values underneath 60 mm hg is generally considered with the requirement for supplemental oxygen. the normal pulse oximeter readings generally range between 95 to 100 percent. the values under 90 percent are regarded as low.  

in the given case, the oxygen saturation is measured at 93 percent, hence, there is no need to administer oxygen, that is, one should withhold oxygen.