| A | B |
|---|
| Host cell | cell in which a virus reproduces |
| T Cell | immune system cell which is the host to HIV virus |
| Natural selection | mechanism that explains how changes in populations occur when organism with favorable variations survive, reproduce and pass on genes |
| adaptations | evlolution of structural, internal or behavioral features that help an organism better survive in its environment |
| homologous structures | structures that have different organisms but develop fromt eh same embryonic tissue |
| ecosystem | populations in a community and abiotic factors with ehich they interact |
| food chain | a possible route for the transfer of matter and energy through an ecosystem |
| food pyramid | summarizes interactions of matter and energy at each trophic level |
| producers | organisms that produce energy |
| consumers | organisms that get energy by eating other organisms |
