9. Terrestrial animals are generally either ureotelic or uricotelic, not ammonotelic, why ?
Terrestrial animals are either ureotelic or uricotelic, and not ammonotelic because of the following two reasons:
1. Since ammonia is highly toxic in nature, it needs to be converted into a less toxic form such as urea or uric acid.
2. Terrestrial animals need to conserve water. Ammonia being soluble in water, cannot be eliminated continuously. Hence, it needs to be converted into urea or uric acid which are insoluble in water. This helps terrestrial animals conserve water.