Biology. A chemical compound regarded as the agent of a specific response in the body; a molecule carrying (esp. genetic) information. See also me…

a substance that genetically transforms bacterial cells (transform, v. 1f).

The smallest element of genetic material that when altered can give rise to a mutation (usually identified as a single base pair). Cf. recon, n.2

The region of a prokaryotic cell where the genetic material is located. Cf. nucleoid, n. 2. rare.

The smallest element of genetic material that can be exchanged but not divided by recombination, now identified as a nucleotide. Cf. muton, n.

Genetics. A bacteriophage which transfers genetic material from one bacterium to another; also, a phage or plasmid used to transfer extraneous DNA…

A unit of coordinated gene activity which regulates protein synthesis in prokaryotes, consisting of a linear sequence of structural genes with one…

Microbiology. In form R. Denoting certain plasmids which confer antibiotic resistance on bacteria and which are often transmissible between…

A unit of the genetic code, comprising the smallest group of nucleotides in a DNA (or other polynucleotide) molecule that determines which amino…

A unit of genetic replication; spec. a nucleic acid molecule, or part of one, containing a single replication origin.

A group of genes, comprising one or more operons, whose transcription is regulated by a single inducer or repressor.

Genetics. A DNA sequence located upstream of a gene to which an RNA polymerase binds and initiates transcription.

Genetics. = promoter, n. 4c.

A plasmid or a bacterial cell which has received genetic material by conjugation with another bacterium.

Genetics. A block of genetic material which can be readily inserted into a chromosome or moved between locations on a genome as a single unit, esp.…