All living things take in food to provide nourishment for the cells, but not all of the food taken in can be used by the body. Once the nutrients have been extracted what is left is waste and the body, whether animal or plant, must eliminate it. This series of slides shows students some of the methods and structures developed by living things for the excretion of waste materials. 1. Paramecium - wm/st (150X) 2. Hydra - cs/st (175X) 3. Leaf stomata - cs/st (275X) 4. Kidney - ls/st (5X) 5. Glomerulus - cs/st (160X) 6. Sweat gland - cs/st (50X) 7. Lung - cs/st (110X) 8. Frog's cloaca - dissection (2X)