Question

How are animals classified on the basis of their excretory products?

Answer 1

Excretion:

• Excretion is the process of releasing waste products from our bodies.
• The organs involved in the process of excretion include a pair of kidneys, a pair of the ureter, urinary bladder, and urethra.
• Different organisms have different molecules as the main component of their excretory products.
• Based on excretory products, animals are classified into three categories:

1. Ammonotelic: Those animals who have ammonia as the major component in their excretory waste are called ammonotelic animals. Most of the aquatic animals, especially fishes, are ammonotelic. The phenomenon of having ammonia as the major excretory product is called ammonotelism.
2. Ureotelic: Those animals with urea as the major component in their excretory waste are called ureotelic animals. Humans represent a good example of ureotelic organisms. Our body requires 50 ml of water to eliminate 1 gram of urea.
3. Uricotelic: Those animals who have uric acid as the major component in their excretory waste are called uricotelic animals. Birds and lizards are mostly uricotelic animals. Our body requires 10 ml of water to eliminate 1 gram of uric acid.