Excretion is the process of eliminating waste materials produced through metabolic activity from living organisms. Some will be toxic and dangerous if not expelled. In Humans - Excretion in the form of the following organs: - Kidneys: The kidney gets rid of nitrogenous waste in the form of urea and uric acid through urine. - Lungs: The lung excretes carbon dioxide and water vapor. - Skin: The skin is responsible for removing waste materials through sweat, containing water, salts, and small amounts of urea. In Plants - Waste products are eliminated by: - Stomata: These release oxygen (from photosynthesis) and carbon dioxide (from respiration). - Storage: Some waste products are stored in leaves, bark, or vacuoles which are ejected from the fallen part whenever shed. Importance: Excretion is important because it fosters homeostasis and a healthy life of an organism as it expels any dangerous substances from its body.

Excretion means removal of harmful, unwanted, toxic metabolic waste from the body of organisms.