Summary
Bacteria change genetically through mutation and by exchanging DNA by transformation, transduction and conjugation.
In depth
Mutation rates are about 10^-9 to 10^-10 per base per division, but huge populations produce much variation. Horizontal transfer brings new genes. Regulation through operons.
Mutations and gene transfer create diversity. Genes are often organised in operons. Whole-genome sequencing reveals pathogen evolution.
Key idea: bacteria swap genes even between species.
Bacteria are haploid, so mutations show up at once, which makes them good for genetics. Gene regulation is often by operons, and the genome of E. coli K-12 has about 4.6 million base pairs and 4300 genes. Mutations can be selected by plating on antibiotics, and the Ames test uses Salmonella strains to detect chemical mutagens by reversion to growth.
Luria and Delbruck (1943) showed that resistance mutations arise randomly before selection, not in response to it, using fluctuation tests. Mobile elements, such as insertion sequences and transposons, rearrange genomes. Genomic islands carry virulence genes.
Frequently asked questions
What is Bacterial Genetics?
Bacteria change genetically through mutation and by exchanging DNA by transformation, transduction and conjugation.
Which area of biology covers Bacterial Genetics, and how advanced is it?
Bacterial Genetics is one of the 54 topics in Microbiology. It is rated Intermediate, so it suits learners who already know the core vocabulary. Related topics in this area include Horizontal Resistance Spread, Microbial Taxonomy, Plasmids.
Why does Bacterial Genetics matter?
Bacterial genetics gave the tools of recombinant DNA, such as restriction enzymes and plasmid vectors.
Can you give an example of Bacterial Genetics?
Griffith's 1928 experiment showed transformation of harmless pneumococcus into virulent form.
What should I learn before Bacterial Genetics?
Work through the Beginner topics in Microbiology first, such as Microorganisms, Bacteria, Archaea, then return to Bacterial Genetics. Intermediate topics assume the Beginner vocabulary.
What topics are related to Bacterial Genetics?
The closest topics to Bacterial Genetics are Horizontal Resistance Spread, Microbial Taxonomy, Plasmids, Conjugation. Comparing them side by side is a good way to see how the ideas connect.
How can I check that I understand Bacterial Genetics?
Read the summary and the in-depth section, then use the quick check on the interactive lesson for Bacterial Genetics. To practise the whole of Microbiology, use the Microbiology quiz.
How is Bacterial Genetics different from Horizontal Resistance Spread?
Bacterial Genetics: Bacteria change genetically through mutation and by exchanging DNA by transformation, transduction and conjugation. Horizontal Resistance Spread: Mobile genetic elements such as integrons and transposons rapidly distribute resistance across species. Read both side by side and note what each one explains.
How should I study Bacterial Genetics step by step?
First, read the summary and write the definition in your own words. Second, read the in-depth section and note any example. Third, compare it with Horizontal Resistance Spread and explain the difference aloud. Finally, take the Microbiology quiz and come back to this page for any question you miss.