Ammonia is toxic and must be secreted as a dilute solution.Why do most freshwater fish secrete ammonia,but mammals do not?
A) Freshwater fish do not have enough energy to convert ammonia to urea.
B) Mammals do not break proteins down forming ammonia.
C) Mammals do not secrete wastes in solution.
D) Freshwater fish can release ammonia without becoming dehydrated by drinking water.
E) Mammals can synthesize urea from ammonia without using energy.

Question

Quizplus · Accepted Answer

The toxicity of ammonia is mitigated for freshwater fish because they can secrete it in a dilute form, but mammals, for which freshwater is at a much greater premium, use urea, which can be held at much higher concentration as it is less toxic.

Ammonia Is Toxic and Must Be Secreted as a Dilute