microbio chapter 8
competent
a bacterial cell that can take up DNA from the surrounding environment
mutation
a change in the nucleotide sequence of DNA that is passed on to daughter cells
mutagen
an agent that induces changes in DNA
prototroph
an organism that does not require growth factors
competent cells
cells that have the ability to take up DNA from the environment
plasmids
circular pieces of bacterial DNA that do not usually encode information essential to the life of a cell
wild type
describes cells that carry non-mutated DNA
genotype
describes the sequence of nucleotides (genetic makeup) of an organism or a cell
core genome
genes that are present in all strains of a given species
mobile genetic elements
genes that vary considerably among strains of a species
induced mutation
genetic changes caused by factors from outside of the cell such as radiation or chemicals
recombinants
horizontal gene transfer occurs between a donor and recipient cells, cells result as this
conjunction
in bacteria this refers to DNA transfer requiring cell to cell contact
transduction
mechanism by which bacterial DNA is moved from one bacterium to another by a bacteriophage
transformation
mechanism of gene transfer involves the uptake of "naked" DNA by competent bacterial receipt cells
auxotroph
mutant that requires a growth factor
point mutation
occurs if a single base pair is changed during DNA synthesis
phenotype
organism observable characteristics
replica plating
plating bacteria in a duplicate patterns on both a nutrient agar plate and a glucose-salts agar plate
frameshift
results in the production of a shortened and non-functional protein because a different set of codons is translated
pre-genome
sum total of genes encoded by all strains of a given species
base substitution
the most common type of mutation where an incorrect nucleotide is incorporated during DNA replication
genotype
the nucleotide sequence in the DNA of a cell or an organism
reversion
the return of a gene from a mutated state to its original, non-mutated state
reactive oxygen species (ROS)
these chemicals, produced in aerobic environments, resulting in increased base substitution because they oxidize guanine in DNA
mobilome
total set of mobile genetic elements
generalized transduction
transfers any genes of the donor cell
specialized transduction
transfers only a few specific genes
generalized transduction
type of transduction that can transfer any genes of a host cell
indirect selection
used to isolate an auxotroph from a prototrophic parent strain, because no selective medium exists to inhibit the. parent
vertical gene transfer
DNA is passed from a parent cell to its progeny
horizontal gene transfer
DNA moves from one organism to another
