| A | B | 
| Pseudopod | A temporary, foot-like extension of a cell, used for locomotion or engulfing food | 
| Nucleus | The region of a eukaryotic cell that contains the cell's main DNA | 
| Vacuole | A membrane-bounded "sac" within a cell | 
| Ectoplasm | The thin, watery cytoplasm near the plasma membrane of some cells | 
| Endoplasm | The dense cytoplasm found in the interior of many cells | 
| Flagellate | A protozoan that propels itself with a flagellum | 
| Pellicle | A firm, flexible coating outside the plasma membrane | 
| Chloroplast | An organelle containing chlorophyll for photosynthesis | 
| Chlorophyll | A pigment necessary for photosynthesis | 
| Eyespot | A light-sensitive region in certain protozoa | 
| Symbiosis | A close relationship between two or more species where at least one benefits | 
| Mutualism | A relationship between two or more organisms of different species where all benefit from the association | 
| Commensalism | A relationship between two organisms of different species where one benefits and the other is neither harmed nor benefited | 
| Parasitism | A relationship between two organisms of different species where one benefits and the other is harmed | 
| Cilia | Hairlike projections that extend from the plasma membrane and are used for locomotion | 
| Spore | A reproductive cell with a hard, protective coating | 
| Plankton | Tiny organisms that float in the water | 
| Zooplankton | Tiny floating organisms that are either small animals or protozoa | 
| Phytoplankton | Tiny floating photosynthetic organisms, primarily algae | 
| Thallus | The body of a plant-like organism that is not divided into leaves, roots, or stems | 
| Cellulose | A substance (made of sugars) that is common in the cell walls of many organisms | 
| Holdfast | A special structure used by an organism to anchor itself | 
| Sessile Colony | A colony that uses holdfasts to anchor itself to an object |