Question

The following are the excretory products in animals. Choose the least toxic nitrogenous excretory product from the following.

• A. Urea
• B. Uric acid
• C. Ammonia
• D. Carbon dioxide

Answer 1

The correct option is B Uric acid

Uric acid is the least toxic excretory product. Insects, land tortoises, lizards and birds convert most of their nitrogenous wastes into uric acid. It is least toxic and is insoluble in water as these are in solid form, thus, contains the least water.

Ammonia is very toxic and needs more water for elimination. Ammonia is converted into less toxic urea in the liver of certain animals like mammals and terrestrial amphibians.

Carbon dioxide excretion takes place through the lungs and it is not a nitrogenous excretory product.