The independent variable is the one variable you manipulate in the experiment
The dependent variable (or responding variable) changes as a result of the independent variable
"A nephron is used to separate water, ions, and small molecules from the blood, filter out wastes and toxins, and return needed molecules to the blood."
https://biologydictionary.net/nephron/
Answer:
Protection from infection known as species resistance is a result of both the absence of necessary receptors and lack of suitable environment in the body.