| Term | Meaning |
| Cell | The smallest unit that builds a living body and runs its life processes |
| Cytology | The science that studies cells |
| Cell theory | The accepted idea that all living bodies are made of cells and that the cell is the basis of life |
| Biochemical reaction | The chemical change inside a cell by which a life process is carried out |
| Structural unit | The basic unit out of which a body is built |
| Functional unit | The basic unit that carries out the life processes |
| Petiole | The stalk that joins a leaf to the branch |
| Temporary slide | A specimen slide made to be used only for a short time |
| Safranin | A stain that colours plant cells red |
| Methylene blue | A stain that colours animal cells blue |
| Glycerine | A thick liquid that keeps the specimen on a slide from drying |
| Mycoplasma | The bacterium that has the smallest known cell |
| Micrometre | A unit of length equal to one millionth of a metre |