The main components of the human excretory system include a pair of kidneys, a pair of ureters, a urinary bladder, and a urethra.

Complex multicellular organisms have higher metabolic rates and generate larger quantities of metabolic wastes compared to unicellular organisms. Specialized excretory organs are necessary to efficiently remove these wastes from the body and maintain internal homeostasis, ensuring the organism’s overall health ...

Complex multicellular organisms use specialized organs, such as kidneys, lungs, and skin, to perform excretion. These organs filter metabolic wastes from the blood or body fluids and eliminate them from the body through various mechanisms, such as urine production, exhalation ...

Unicellular organisms often remove metabolic wastes by simple diffusion from the body surface into the surrounding water. This process allows for the direct elimination of wastes into the external environment without the need for specialized excretory organs.

Excretion is the biological process of removing harmful metabolic wastes from the body. It is essential for maintaining internal homeostasis by eliminating toxic substances that can accumulate and disrupt normal physiological functions.