Although they are haploid and reproduce asexually, prokaryotes have the ability to transfer genes from one cell to another. These genes are usually carried on small, circular DNA molecules called plasmids, but chromosomal DNA is sometimes transferred as well.
learning outcomes
You should be able to:
Outline the steps involved in the transfer of genetic material by bacterial conjugation.
Explain the significance of mating and genetic recombination in prokaryotes.
Discuss the genetic significance of mating and recombination in bacteria.
Mating and recombination allows genes to be exchanged between bacteria and results in a genetically diverse population of these organisms. Because they are haploid, any new gene combinations will be expressed in the recombined offspring.
What is the potential consequence of a plasmid being integrated into the main chromosome of a prokaryotic cell?
A plasmid that integrates into the host chromosome will be stable when the cell divides and therefore any genes on the plasmid will be expressed. In addition, if the bacterium mates, the genes on the plasmid may be transferred to another cell.
How does antibiotic resistance spread via plasmids?
Plasmids can carry genes that confer antibiotic resistance. When a bacterium carry a plasmid mates with one that does not, the plasmid replicates and transfers one of the copies to the recipient bacterium. Now there are two bacteria with antibiotic resistance.