DNA damage mutagenesis + DNA repair Flashcards
What is a mutant
Organism whose DNA sequence differs from the wildtype
What are conditional mutants?
Mutants which do not always exhibit the phenotype dependant on environment or genetic background
Give an example of a conditional mutant
Temperature sensitive mutants
What is a point mutation?
Single base pair mutation
What is a double mutation?
Two base pairs are mutated
What is an inversion mutation?
Segment of DNA reverses its own orientation
What do base substitutions result in?
A change to the codon itself resulting to a different amino acid being created
How do frame shifts effect a sequence?
The addition of just a single base pair will result in all additonal codons being incorrect
How can a cell attempt to repair a frameshift?
Add or remove bases until 3n is reached
What factors determine frequency of mutations?
- Population size
- Gene size
- Type of mutation
What causes mutations to occur?
- Replication errors
- Nucleotide tautomerism
- Spontaneous alterations of nucleotides
How can you induce a mutant?
Exposure to a mutagen
Give an example of a mutagen
- Radiation
- Base analoguses
How do intercalating agents result in mutation?
Insert themselves between base pairs, Tricking the polymerase into skipping or inserting bases
How can you use selection to isolate mutants?
Create a plate and conditions where you only want the desired mutants to grow
