[Campbell Biology P.1046] Which of the following pairs correctly matches a type of nitrogenou... | Practice Question

Which of the following pairs correctly matches a type of nitrogenous waste with an animal group and its characteristic property regarding water conservation?

  • A: Ammonia – Mammals – Excreted with minimal water loss.
  • B: Urea – Aquatic animals – Highly insoluble waste, excreted in paste-like urine.
  • C: Uric acid – Insects and reptiles – Requires significant water for excretion.
  • D: Urea – Adult amphibians – Less toxic than ammonia, excreted with minimal water loss.

Explanation

The text states that "Mammals and most adult amphibians convert ammonia to the less toxic urea, which is excreted with a minimal loss of water." This directly matches option D. Ammonia is highly toxic and requires large amounts of water for excretion, typically by aquatic animals. Uric acid is the most water-conserving waste, excreted in a paste-like form by insects and many reptiles, not requiring significant water.