smallest working part of a living organism.
series of organs and glands responsible for the ingestion, digestion, and absorption of food. Also called the alimentary canal.
tubular system in the human digestive system, which regulates elimination of waste products from the body.
cells, organs, and tissues including the brain and spine that respond to internal and external stimuli.
musical instrument made of pipes that release different sounds when a keyboard forces air through them.
cells that form a specific function in a living organism.