| A | B |
|---|
| prokaryote | unicellular organism lacking a nucleus |
| bacillus | rod-shaped prokaryote |
| coccus | spherical prokaryote |
| spirillum | spiral or corkscrew-shaped prokaryote |
| chemoheterotroph | organism that must take in organic molecules for both energy and carbon |
| photoheterotroph | organism that is photosynthetic but needs organic compounds as a carbon source |
| photoautotroph | organism that uses energy from sunlight to convert carbon dioxide and water into carbon compounds |
| chemoautotroph | organism that makes organic carbon molecules from carbon dioxide using energy from chemical reactions |
| obligate aerobe | organism that requires a constant supply of oxygen in order to live |
| obligate anaerobe | organism that cannot live in the presence of oxygen |
| facultative anaerobe | organism that can survive with or without oxygen |
| binary fission | type of asexual reproduction in which an organism replicates its DNA and divides in half, producing two identical daughter cells |
| conjugation | form of sexual reproduction in which paramecia and some prokaryotes exchange genetic information |
| endospore | type of spore formed when a bacterium produces a thick internal wall that encloses its DNA and a portion of its cytoplasm |
| nitrogen fixation | process of converting nitrogen gas into ammonia |
| virus | particle made up of nucleic acid, protein, and in some cases lipids that can replicate only by infecting living cells |
| capsid | outer protein coat of a virus |
| bacteriophage | virus that infects bacteria |
| lytic infection | process in which a virus enters a cell, makes a copy of itself, and causes the cell to burst |
| lysogenic infection | process by which a virus embeds its DNA into the DNA of the host cell and is replicated along with the host cell's DNA |
| prophage | the viral DNA that is embedded in the host cell's DNA |
| retrovirus | virus that contains RNA as its genetic information |
| pathogen | disease-causing agent |
| vaccine | a preparation of weakened or killed pathogens |
| antibiotic | compound that blocks the growth and reproduction of bacteria |
| viroid | single-stranded RNA molecule that has no surrounding capsids |
| prion | infectious particle made up of protein rather than RNA or DNA |
