Exchange Surfaces Practice Test 2025 – 400 Free Practice Questions to Pass the Exam

Uric acid is primarily associated with terrestrial reptiles and birds due to their adaptations for conserving water. These organisms excrete nitrogenous waste as uric acid, which is a relatively insoluble compound. This allows them to minimize water loss compared to organisms that excrete urea or ammonia, especially in arid environments where conserving water is crucial for survival.

By forming uric acid as a solid or semi-solid, these animals can excrete nitrogen waste without losing significant amounts of water, enabling them to thrive in diverse habitats. While mammals produce urea, aquatic organisms often excrete ammonia directly due to the abundance of water in their environments, which aids in diluting the toxic nitrogenous wastes. Similarly, plants do not produce uric acid but instead utilize nitrogen in various other forms for growth. Thus, the association of uric acid with terrestrial reptiles and birds highlights their specific evolutionary adaptations to land.