Question

The snakes living in deserts are mainly
A. Ammonotelic
B. Aminotelic
C. Ureotelic
D. Uricotelic

Answer 1

Hint: Excretion in desert snakes occurs by absorbing water and eliminating solid uric acid. In desert reptiles and birds need to conserve water from their body in order to prevent loss of water.

Complete answer:
In the liver and to some extent in the kidney, ammonia gets converted into uric acid.
This process is more energy-intensive than compared with the conversion of ammonia into uric acid.
The benefits of conversion of ammonia into uric acid are, it is less toxic than urea, almost insoluble in water, during elimination from the body it can be excreted in solid form and therefore saving lots of water. As there is a scarcity of water in the desert water from the body should be prevented from eliminating.
Reptiles and birds pass dilute solution of uric acid into cloaca as the kidney handles nitrogenous waste only in solution form.
In it, the water is absorbed and faeces are excreted in solid uric acid form.
Reptiles and birds which excrete their nitrogenous waste in uric acid form are called uricotelic.

So, the correct answer is option D) Uricotelic.

Note: The organisms which excrete nitrogenous waste in the form of ammonia are known as Ammonotelic. It is highly toxic and produced by quick diffusion into water. Seen in freshwater fishes and many aquatic invertebrates.
Aminotelic is organisms which excrete nitrogenous waste in the form of amino acids. Seen in molluscs like Unio, Limnaea etc., and some echinoderms like Asterias.
Ureotelic are the organisms that excrete nitrogenous waste in the form of urea. It is less toxic than ammonotelic. Mammals including humans excretion are ureotelic.