Ch 10 - Genetics of Bacteria and Archaea Flashcards
Heritable change in DNA sequence that can lead to a change in phenotype
mutation
A strain of any cell or virus differing from parental strain in genotype
mutant
Typically refers to strain isolated from nature
wild type strain
mutations that give the mutant a growth advantage under certain conditions
selectable mutations
mutations that usually have neither an advantage nor a disadvantage over the parent
nonselectable mutations
Detection of such mutations requires examining a large number of colonies and looking for differences (screening)
nonselectable mutations
_______ __________ is useful for identification of cells with a nutritional requirement for growth
Replica plating
Mutations made environmentally or deliberately
induced mutations
mutations that Can result from exposure to natural radiation or oxygen radicals
induced mutations
mutations that occur without external intervention
spontaneous mutations
Mutations that change only one base pair
point mutations
Deletions or insertions that result in a shift in the reading frame
frameshift mutations
Often result in complete loss of gene function
frameshift mutations
process where point mutations are typically reversible
reversion
Strain in which original phenotype is restored
revertant
mutation is at the same site as original mutation
same-site revertant
mutation is at a different site in the DNA
second-site revertant
chemical, physical, or biological agents that increase mutation rates
mutagens
mutagens that resemble nucleotides
Nucleotide base analogs
give an example of non-ionizing electromagnetic radiation
radiation
______ and ______strongly absorb UV
Purines and pyrimidines
give an example of ionizing mutagenic electromagnetic radiation
x-rays, cosmic rays, gamma rays
this type of electromagneti radiation Ionizes water and produce free radicals
ionizing
DNA repair system where mutated base is still recognizable and can be repaired without referring to other strand
direct reversal
DNA repair system where damaged DNA is removed and repaired using opposite strand as template
repair of single strand
DNA repair system to repair a break in the DNA
repair of double-strand damage
Physical exchange of DNA between genetic elements
recombination
Process that results in genetic exchange between homologous DNA from two different sources
homologous recombination
Genetic transfer process by which DNA is incorporated into a recipient cell and brings about genetic change
transformation
who discovered transformation?
Fredrick Griffith
cells capable of taking up DNA and being transformed
competent cells
Transfer of DNA from one cell to another by a bacteriophage
transduction
mechanism of genetic transfer that involves cell-to-cell contact
bacterial conjugation (mating)
contains conjugative plasmid
donor cell
cell that does not contain plasmid
recipient cell
cells that can’t take up DNA
non-competent cells
Electricity can be used to force cells to take up DNA
electroporation
Discrete segments of DNA that move as a unit from one location to another within other DNA molecules are ________
transposable elements
transposable elements move by a process called ______
transposition
Two main types of transposable elements in Bacteria are _______ and __________
transposons and insertion sequences
what are the two characteristics of the transposons and insertion sequences?
1) genes encoding transposase
2) recognition sites at both ends
Changes codon so it encodes for the wrong AA
missense mutation
Changes codon so it encodes for a stop codon
nonsense mutation
Changes codon so it encodes for correct amino acid
silent mutation
