| A | B |
|---|
| Eubacteria | cell walls contain peptidoglycan |
| Archaebacteria | found in extreme environments |
| bacillus | rod-shaped bacterium |
| binary fission | cell divides into two equal parts |
| obligate aerobe | bacteria that cannot survive without oxygen |
| coccus | round-shaped bacteria |
| nitrogen fixation | bacteria convert nitrogen gas to ammonia |
| pathogen | a disease-causing agent |
| spirillum | spiral-shaped bacteria |
| Gram-positive | retain the Gram stain and appear purple |
| conjugation | genetic material is transferred through a tube |
| obligate anaerobe | bacteria that die when exposed to oxygen |
| endospore | hard, protective outer covering |
| Gram-negative | do not retain purple stain and take up a second pink stain |
| facultative anaerobe | bacteria that survive with or without oxygen |
