| A | B |
| protozoan | An animal-like protist. |
| pseudopod | A "false foot" or temporary bulge of the cell membrane used for feeding and movement in some protozoans. |
| contractile vacuole | The cell structure that collects extra water from the cytoplasm and then expels it from the cell. |
| cilia | The hairlike projections on the outside of cells that move in a wavelike manner. |
| symbiosis | A close relationship between two organisms in which at least one of the organisms benefits. |
| mutualism | A type of symbiosis in which both partners benefit from living together. |
| spore | A tiny cell that is able to grow into a new organism. |
| algae | Plantlike protists. |
| pigment | A chemical that produces color. |
| algal bloom | The rapid growth of a population of algae. |
| red tide | An algal bloom that occurs in salt water. |
| eutrophication | The buildup over time of nutrients in freshwater lakes and ponds that leads to an increase in the growth of algae. |
| hypha | One of many branching, threadlike tubes that make up the body of a fungus. |
| fruiting body | The reproductive hypha of a fungus. |
| budding | A form of asexual reproduction of yeast in which a new yeast cell grows out of the body of a parent. |
| lichen | The combination of a fungus and either an alga or an autotrophic bacteria that live together in a mutualistic relationship. |