| A | B |
|---|
| Single-celled (unicellular) | Made of a single cell |
| Multicellular | Made of more than one cell |
| Prokaryote | A single-celled organism that does not have a nucleus or membrane-bound organelles; examples are archaea and bacteria |
| Eukaryote | An organism made up of cells that have a nucleus enclosed by a membrane; eukaryotes include protists, animals, plants, and fungi but not archaea or bacteria |
| Organism | A living thing; anything that can carry out life processes independently |
| Photosynthesis | The process by which plants, algae, and some bacteria use sunlight, carbon dioxide, and water to make food |
| cellular respiration | the process by which cells use oxygen to produce energy from food |
| spontaneous generation | a theory held for some time that living things arise from nonliving sources |
| Pasteurization | A process of heating food to a temperature that is high enough to kill most harmful bacteria without changing the taste of the food. |
| Anton Van Leuwenhoek (1665) | credited for inventing the microscope |
| Robert Hooke (1665) | first to observe "small chambers" in cork and call them cells. |
| Francesco Redi (1668) | Showed maggots do not arise from decaying meat (discrediting spontaneous generation theory) |
| Louis Pasteur (1862) | Showed microbes caused fermentation and spoilage |
