Which of the Following Pairs of Organisms Excrete Nitrogenous Wastes

Question

Which of the following pairs of organisms excrete nitrogenous wastes in the form of uric acid?
A) mice and birds
B) insects and birds
C) lions and horses
D) humans and frogs
E) fish and turtles

Accepted Answer

Both insects and birds excrete nitrogenous wastes in the form of uric acid, as they have evolved to conserve water in their bodies. This allows them to excrete nitrogenous wastes in a solid form, rather than a liquid form like urea or ammonia. Mice, lions, horses, humans, fish, and turtles all excrete nitrogenous wastes in the form of urea or ammonia. Frogs excrete nitrogenous wastes in the form of ammonia during their aquatic tadpole stage, but switch to urea or uric acid once they become terrestrial adults.