Unit Three- Gene EXpression Mutations Flashcards
what is a mutations
a permanent change in the nucleotide sequence of cells in DNA
what happens if a mutation is silent
it is not detected
what does a single gene mutation effect
effects the coding sequence of one gene
what is a point mutation
single gene mutation
single gene base pair undergoes insertion, deletion, or substitution
what does a chromosomal mutation effect
may occur in chromosomes affecting many genes
what are the 4 single gene mutations
-silent
-missense
-non sense
-frameshift
what does a silent mutation do
produces a triplet codon that codes for the same amino acid
what does a missense mutation do
results in the single SUBSTITUTION of one amino acid in the protein
what does a nonsense substitution do
-also called a termination mutation
-converts an amino acid codon to a stop codon
-lethal to the cell
what does a frameshift mutation do
the reading frame is shifted
-base pair deletion or base pair insertion
-changes remainder of the code
-usually lethal
-no useful protein is produced
what are the two chromosomal mutations
translocational and inversion
what does a translocation mutation do
chuck of the chromosome is relocated from one area to another
-between two non homologous chromosomes
results in a fusion protein
what does inversion mutation do
segment of chromosome reverses its orientation
what factors deem soemthing a spontaneous mutation
-normal condition
-mispairing during replication
-transponsons- movement of DNA segments within and between chromsomes
what deems something an induced mutation
-environmental mutagens
-physical mutagens (high energy radiation)
-chem. mutagen (chem that reacts with DNA causing nucleotide substitution)
