| A | B |
|---|
| activator | stimulates transcription of a specific gene |
| AIDS (acquired immunodeficiency syndrome) | infection |
| bacteriophage | virus that infects bacteria |
| capsid | protein shell that encloses a viral genome |
| conjugation | direct transfer of DNA between two cells that are temporarily joined |
| corepressor | molecule that cooperates with a repressor protein to switch on operon off |
| cyclic AMP (cAMP) | cyclic adenosine monophosphate a signaling molecule in eukaryote cells |
| episome | genetic element that can exist either as a plasmid or as part of the bacterial chromosome |
| F factor | DNA segment that confers the ability to form pili for conjugation |
| F plasmid | plasmid form of the F factor |
| HIV (human immunodeficiency virus) | infectious agent that causes AIDS |
| host range | limited range of host cells that each type of virus can infect |
| inducer | inactivates the repressor in an operon |
| insertion sequence | inverted repeats of DNA flanking a gene for transposase |
| lysogenic cycle | viral genome is added into the bacterial host chromosome as a prophage and does not kill the host |
| lytic cycle | resulting in the release of new phages by lysis (and death) of the host cell |
| nucleoid | dense region of DNA in a prokaryotic cell |
| operator | nucleotides near the start of an operon to which an active repressor can attach |
| operon | regulated clusters of genes with related functions |
| phage | virus that can infect a bacterial cell |
| plasmid | small ring of DNA that carries accessory genes separate from those of a bacterial chromosome |
| prion | infectious form of protein |
| prophage | phage genome that has been inserted into a specific site on the bacterial chromosome |
| provirus | Viral DNA that inserts into a host genome |
| R plasmid | plasmid carrying genes that confer resistance to certain antibiotics |
| regulatory gene | codes for a protein |
| repressor | protein that suppresses the transcription of a gene |
| retrovirus | RNA virus that reproduces by transcribing its RNA into DNA |
| reverse transcriptase | enzyme in certain viruses (retroviruses) that uses RNA as a template for DNA synthesis |
| temperate phage | capable of reproducing by either the lytic or lysogenic cycle |
| transduction | process in which phages carry bacterial genes from one host cell to another |
| transformation | in genotype and phenotype due to the assimilation of external DNA by a cell |
| transposable genetic element | segment of DNA that can move within the genome of a cell |
| transposon | transposable genetic element |
| vaccine | harmless variant or derivative of a pathogen that stimulates a host’s immune system |
| viral envelope | membrane that cloaks the capsid that in turn encloses a viral genome |
| viroid | plant pathogen composed of molecules of naked circular RNA |
| virulent phage | phage that reproduces only by a lytic cycle causing death of its host cell |
