| A | B |
|---|
| organism | A living thing. |
| cell | The basic unit of structure and function in an organism. |
| unicellular | An organism made up of one cell. |
| multicellular | An organism made up of many cells. |
| development | The process of change that occurs during an organism's life to produce a more complex organism. |
| stimulus | A change in an organism's surroundings that causes the organism to react. |
| response | An action or change in behavior that occurs as a result of a stimulus. |
| reproduce | The production of offspring that are similar to the parents. |
| spontaneous generation | The mistaken idea that living things arise from nonliving sources. |
| controlled experiment | An experiment in which all factors are identical except one. |
| variable | Any factor that can change in an experiment. |
| autotroph | An organism that makes its own food. |
| heterotroph | An organism that cannot make its own food. |
| homeostasis | The maintenance of stable internal conditions despite changes in the surroundings. |
| fossil | The trace of an organism that has been preserved in rock. |
| classification | The process of grouping things based on their similarities. |
| taxonomy | The scientific study of how living things are classified. |
| binomial nomenclature | The naming system for organisms in which each organism is given a two-part name: a genus name and a species name. |
| genus | A classification grouping that consists of a number of similar, closely related species. |
| species | A group of similar organisms that can mate and produce fertile offspring in nature. |
| taxonomic key | A series of paired statements that describe the physical characteristics of different organisms. |
| prokaryote | An organism whose cells lack a nucleus and some other structures. |
| eukaryote | An organism with cells that contain nuclei and other cell structures. |
