The Principal Nitrogenous Waste of Sea Stars Is

Question

The principal nitrogenous waste of sea stars is
A)urea.
B)uric acid.
C)urine.
D)guanine.
E)ammonia.

Accepted Answer

Sea stars are marine animals and, thus, excrete ammonia as their principal nitrogenous waste. Ammonia is highly soluble in water and can be eliminated efficiently through the gills or dermal papillae of sea stars. Urea and uric acid are commonly found in terrestrial animals as their nitrogenous wastes, while guanine is a nitrogenous base found in DNA and RNA but not excreted as waste. Urine is a liquid waste product produced by the kidneys in mammals and some other animals.