Chapter 18 Flashcards
(30 cards)
Base substitution
Change of DNA base results in a changed codon
Base insertion or deletion
Addition or deletion of base, alters reading frame and may change many codons
Types of base substitution
Transitions and transversions
Transitions
Purine to purine or pyrimidine to pyrimidine
Transversions
Purine to pyrimidine or pyrimidine to purine
Frameshift mutation
Alters all subsequent codons
In-frame insertion
Addition or deletion in multiple of 3, does not change reading frame
Forward mutation
Wild type to mutant type
Reverse mutation
Mutant type to wild type
Missense mutation
Alterred codon encodes a different amino acid
Nonsense mutation
Premature stop codon
Silent mutation
Change in codon but codon still encodes the same amino acid as it originally would
Neutral Mutation
Alters amino acid, but not protein function
Conditional mutations
Altered phenotype only observed under specific conditions
Suppressor mutation
A mutation that hides or suppresses the effect of another
incorporation error
Mispaired base during replication
Replicated Errors
Errors during replication that go onto become replicated themselves
Causes of insertions or deletions
Strand slippage (looping out of certain bases); Unequal crossing over
Depurination
Loss of a purine
Deamination
Loss of an amino group
Mutagen
An agent that increases the rate of mutation
Base analogs
Similar to bases, but may result in different pairing
Oxidative Reaction
Superoxide Radicals alter base structure
Intercalating agents
Alter base structure
