Trait controlled by the both environment and genetic factor. Usually, multifactorial traits outside of illness result in what we see as continuous characteristics in organisms, especially human organisms such as: height, skin color, and body mass.
I recently took a drug test for a job. I tested positive for opiates in my urine. I do not and have never taken drugs of any sort other than alcohol. I dont take any prescription drugs, how is it possible that this happened. I hade consumed some beer about12 hours before the test.
Sometimes, they will only test for the presence of opiates, but some doctors, like mine, test which type of opiate. The samples do have to be sent off to a lab for most of these types of tests, but there are new urine cups with a strip on the bottom that can make the distinction between the two. I actually just took one like this today for the first time.