Question

The passing out of almost solid excretory wastes in reptiles is an indication of

• A. Xeric habits
• B. Excretion through skin
• C. Reutilizing water of urine
• D. Both A and C

Answer 1

Answer: (D)

Both A and C

Uric acid and urea represent different adaptations for excreting nitrogenous wastes with minimal water loss. Land snails, insects, birds and many reptiles excrete uric acid as the main nitrogenous waste. Like urea, uric acid is relatively nontoxic. But unlike either ammonia or urea, uric acid is largely insoluble in water and can be excreted as a semi-solid paste with very little water loss. While saving more water than urea, it is even more energetically expensive to produce.

So, the correct answer is option D.