Chapter 8 – Bacterial Genetics
, Bacterial Genetics: Introduction and Background
• Bacteria, like all living organisms, undergo natural selection (“survival of
the fittest”)
• Heritable traits can be passed on from generation to generation either via
binary fission or conjugation (a method of horizontal gene transfer)
• Which survive?
– Resistance can be genotypic and phenotypic
• Genotype: the actual genetic makeup of a gene
• Phenotype: the physical expression of a gene (not always
expressed!)
– Mutation is the raw material of evolution; mutation does not always
create more adaptable organisms, however
• Wild type – dominant, normal phenotype in population
• Mutant – non-dominant, occurs in population rarely, can confer
antibiotic advantage, but not necessarily so
, Bacterial Genetics: Introduction and Background
• Bacteria, like all living organisms, undergo natural selection (“survival of
the fittest”)
• Heritable traits can be passed on from generation to generation either via
binary fission or conjugation (a method of horizontal gene transfer)
• Which survive?
– Resistance can be genotypic and phenotypic
• Genotype: the actual genetic makeup of a gene
• Phenotype: the physical expression of a gene (not always
expressed!)
– Mutation is the raw material of evolution; mutation does not always
create more adaptable organisms, however
• Wild type – dominant, normal phenotype in population
• Mutant – non-dominant, occurs in population rarely, can confer
antibiotic advantage, but not necessarily so
