| A | B |
|---|
| Excretion | removal of waste of cell activities |
| Urea | metabolic waste made when protein breaks down |
| Blood | liquid that transports waste and nutrients |
| Skin | excretory organ that excretes perspiration |
| Lungs | excretory organ that excretes carbon dioxide and water |
| Urine | metabolic waste that contains urea |
| Liver | makes urea |
| Metabolic waste | wastes that are produced in cells |
| Excretory system disorders | disorders of the excretory system |
| Cellular respiration | energy releasing process that takes place in mitochondria |
