Answer:
25.Nitrogenous wastes in the body tend to form toxic ammonia, which must be excreted. Mammals such as humans excrete urea, while birds, reptiles, and some terrestrial invertebrates produce uric acid as waste. Uricothelic organisms tend to excrete uric acid waste in the form of a white paste or powder.
34.The excretory system removes cellular wastes and helps maintain the salt-water balance in an organism. In providing these functions, excretion contributes to the body's homeostasis, the maintenance of constancy of the internal environment. When cells break down proteins, they produce nitrogenous wastes, such as urea
