Which of the following is NOT a function of the excretory system?

The correct answer highlights that the breakdown of fats is not a function of the excretory system. The excretory system is primarily responsible for removing metabolic wastes, regulating blood pressure, and producing urine. It includes organs such as the kidneys, ureters, bladder, and urethra, which work together to filter blood, remove waste products (like urea and creatinine), and maintain homeostasis in the body.

In contrast, the breakdown of fats is a function associated with the digestive and metabolic systems. Specifically, the digestive system is responsible for nutrient absorption and the conversion of fats into usable energy. Moreover, while the excretory system may play a role in the elimination of by-products from fat metabolism, the actual breakdown itself occurs in organs like the liver and involves biochemistry that is separate from excretory functions. Thus, identifying the breakdown of fats as not being a function of the excretory system is accurate.