| Term | Definition |
| Species | a group of organisms that can reproduce with one another in nature and produce fertile offspring. |
| Cell | the smallest unit that can live on its own and that makes up all living organisms and the tissues of the body |
| Eukaryote | organisms whose cells contain a nucleus and other membrane-bound organelles. |
| Response | An action or movement due to the application of a stimulus. |
| Organism | an individual animal, plant, or single-celled life form. |
| Stimulus | anything that can trigger a physical or behavioral change. |
| Asexual reproduction | generates offspring that are genetically identical to a single parent. |
| Development | The series of changes which animal and vegetable organisms undergo in their passage from the embryonic state to maturity, from a lower to a higher state of organization. |
| Multicellular | an organism composed of many cells, which are to varying degrees integrated and independent. |
| Autotroph | an organism that can produce its own food using light, water, carbon dioxide, or other chemicals. |
| Nucleus | the membrane-enclosed organelle within a cell that contains the chromosomes. |
| Metabolism | The chemical changes that take place in a cell or an organism |
| Convergent evolution | the process whereby distantly related organisms independently evolve similar traits to adapt to similar necessities |
| Evolution | the change in the characteristics of a species over several generations and relies on the process of natural selection. |
| Spontaneous generation | the idea that living organisms can spring into existence from non-living matter. |
| Prokaryote | any organism that lacks a distinct nucleus and other organelles |
| Binomial nomenclature | a system of naming plants and animals in which each species is given a name consisting of two terms of which the first names the genus and the second the species itself. |
| Sexual reproduction | the production of new organisms by the combination of genetic information of two individuals of different sexes. |
| Shared derived characteristics | A shared character is one that two lineages have in common. |
| Classification | a system of categorizing living things |
| Heterotroph | an organism that eats other plants or animals for energy and nutrients. |
| Branching tree diagram | a set of groups within groups, with the organisms at the bottom having the fewest shared characteristics and the ones at the top having the most. |
| Taxonomy | the science of naming, describing and classifying organisms |
| Unicellular | A unicellular organism is made of only one cell |
| Genus | a class of similar things, especially a group of animals or plants that includes several closely related species. |
