| Antagonistic | A biological structure or chemical agent that interferes with the physiological action of another. |
| Muscle | A band or bundle of fibrous tissue in a human or animal body that has the ability to contract, producing movement in or maintaining the position of parts of the body. |
| Nucleus | A dense organelle present in most eukaryotic cells, typically a single rounded structure bounded by a double membrane, containing the genetic material. |
| Mitochondria | An organelle found in large numbers in most cells, in which the biochemical processes of respiration and energy production occur. It has a double membrane, the inner part being folded inwards to form layers (cristae). |
| Cell Membrane | The semipermeable membrane surrounding the cytoplasm of a cell. |
| Cytoplasm | The material or protoplasm within a living cell, excluding the nucleus. |
| Vacuole | A space or vesicle within the cytoplasm of a cell, enclosed by a membrane and typically containing fluid. |
| Chloroplast | A plastid in green plant cells which contains chlorophyll and in which photosynthesis takes place. |
| Microscope | An optical instrument used for viewing very small objects, such as mineral samples or animal or plant cells, typically magnified several hundred times. |
| Specialised | Specialised cells. Cells may be specialised for a particular function. Their structure will allow them to carry this function out. |
