Gene Mutation & DNA repair Flashcards
Mutations
Heritable change in genetic material
_________ changes the DNA sequence
Mutations
What are some advantageous of mutations?
Can cause allelic variation & evolution where if detrimental it can be repaired
____________ are molecular changes in the DNA sequence of a gene (changed a nucleotide in DNA)
Gene mutations
What are the 3 different types of gene mutations?
- Substitution (base substitution which is a type of point mutation)
- Deletion
- Insertion
Point mutation
Change in a single base pair in DNA
Base substitution (type of point substitution)
When one base is substituted for another
Transition
A change from one pyrimidine to another pyrimidine base (like C to T) or from one purine base to another purine base (like A to G)
Transversion
Purines & pyrimidines are interchanged
___________ can alter the coding sequences of a gene
Gene Mutation
Silent mutations
Are mutations that don’t change the amino acid that produce (but does change the codon but still get the same amino acid ) (Genetic material redundant)
Missense mutation
Are base substitution that does change the amino acid that is produced (can have minor or major effects)(ex. sickle cell disease)
Nonsense mutation
Involves a change from a normal codon to a stop condon
Frameshift mutations
Involves the insertion or deletion of a number of nucleotides that are not multiples of 3 or dividably by 3 (group of 3)
_____________ shifts the reading frame causing a new reading frame which changes protein sequence after it
Frameshift
Mutation in noncoding sequences can affect ______________
Gene expression
Up promter mutation
Promoters mutation that increase transcription (makes a sequence more like consence sequence)
Down promoter mutations
Decreases transcription rate & causes a promoter to become less like consensus
Coding regions
Is the protein