AP BIOLOGY

Detailed explanation-1: -Animal excretion Feces (poop) is not part of excretion because this does not come from chemical reactions inside cells. Instead feces are the parts of food that never got digested and sent to the cells of the body.

Detailed explanation-2: -Carbon dioxide, urea and water are excreted from the body in one way or the other. Removal of undigested food through the anus is not excretion. This process is called defecation.

Detailed explanation-3: -Excretion is an essential process in all forms of life. For example, in mammals, urine is expelled through the urethra, which is part of the excretory system. In unicellular organisms, waste products are discharged directly through the surface of the cell.

Detailed explanation-4: -excretion, the process by which animals rid themselves of waste products and of the nitrogenous by-products of metabolism. Through excretion organisms control osmotic pressure-the balance between inorganic ions and water-and maintain acid-base balance.