Multiple choice

Excretion is mainly responsible for the removal of

  1. excess of water

  2. carbon dioxide

  3. unnecessary and harmfulproducts

  4. waste products of the animal's own metabolism

Reveal answer Fill a bubble to check yourself
D Correct answer
Explanation

Excretion is defined as the removal of metabolic waste products - substances produced by the body's own metabolic processes that are no longer needed or are harmful. This includes nitrogenous wastes from protein metabolism, CO2 from cellular respiration, and other byproducts. It differs from egestion (elimination of undigested food) and secretion (release of useful substances).