AP BIOLOGY

Detailed explanation-1: -90% of energy is lost in the form of heat energy through respiration, dead organisms, uneaten body parts and excretory products like feces, urine and sweat.

Detailed explanation-2: -Energy that is not used in an ecosystem is eventually lost as heat. Energy and nutrients are passed around through the food chain, when one organism eats another organism.

Detailed explanation-3: -Within all biological communities, energy at each trophic level is lost in the form of heat (as much as 80 to 90 percent), as organisms expend energy for metabolic processes such as staying warm and digesting food (see biosphere: The organism and the environment: Resources of the biosphere: The flow of energy).

Detailed explanation-4: -Excretion is the physiological process of elimination of metabolic waste from the body. The excretory products include amino acids, urea, uric acid, carbon dioxide, water, and ammonia. Some Molluscs and Echinoderms excrete waste products from the body in the form of amino acids.

Detailed explanation-5: -When our cells perform their functions, certain waste products are released. These are toxic and hence need to be removed from the body. The process of removal of wastes produced in the cells of the living organisms is called excretion.