| A | B |
|---|
| virus | A small, nonliving particle that invades and then reproduces inside a living cell. |
| host | An organism that provides a source of energy or a suitable living environment for another organism. |
| parasite | An organism that lives on or in a host and causes harm to the host. |
| bacteriophage | A virus that infects bacteria. |
| cytoplasm | The gel-like material in a cell between the cell membrane and nucleus. |
| ribosome | A tiny structure located in the cytoplasm of a cell where proteins are made. |
| flagellum | A long, whiplike structure that extends out through the cell membrane and cell wall. |
| binary fission | A form of asexual reproduction in which one cell divides to form two identical cells. |
| asexual reproduction | The reproductive process that involves only one parent and produces offspring identical to the parent. |
| sexual reproduction | The reproductive process that involves two parents who combine their genetic material to produce a new organism, which differs from both parents. |
| conjugation | The process in which a unicellular organism transfers some of its genetic material to another unicellular organism. |
| respiration | The process of breaking down food to release its energy. |
| endospore | A small, rounded, thick-walled, resting cell that forms inside a bacterial cell. |
| decomposer | An organism that breaks down large chemicals from dead organisms into small chemicals and returns important materials to the soil and water. |
| infectious disease | An illness that can pass from one organism to another. |
| toxin | A poison that can harm an organism. |
| antibiotic | A chemical that can kill bacteria without harming a person's cells. |
| vaccine | A substance that stimulates the body to produce chemicals that destroy viruses, bacteria, or other disease-causing organisms. |
