| A | B |
|---|
| bacteria | A tiny, single-cell organism that can make people sick |
| contaminant | biological, chemical, physical, or radiological substance which can adversely affect living things through air, water, soil, or food. |
| chlorine | The most common chemical for cleaning water |
| disease | an illness that affects a person, animal, or plant |
| cholera | A disease of the small intestines caused by bacteria |
| sediment | materials that sinks to the bottom of a liquid |
| membrane | A barrier that allows some things to pass through and others not |
| plankton | The collection of small or microscopic organisms, including algae and protozoans, that float or drift in great numbers in water |
| virus | An extremely small living thing that causes a disease and that spreads from one person or animal to another |
| microorganism | A living thing that is too small to see without a microscope |
| Hepatitis A | A disease of the liver caused by contaiminated water |
| Amebiasis | an intestinal illness caused by a microscopic parasite called Entamoeba histolytica. |
