Answer:
If it helps, the answer is Mutualism (let me know if it is for some reason incorrect)
Is that a test your taking?
Answer:
Nitrogenous;Acid-Base and Fluid
Explanation:
The kidney is referred to as an excretory organ because it excretes nitrogenous wastes. It is also a major homeostatic organ because it maintains the electrolyte Acid-Base, and fluid balance of the blood.