Mutations Flashcards
what is a mutation?
a random change in an organisms structure or amounts of genetic material
can result in no protein or an altered protein being synthesised
what are single gene mutations?
a change in a DNA nucleotide sequence in one gene
what are the three types of single gene mutation?
Substitution
Insertion
Deletion
what happens in substitution and what does it result in?
one nucleotide is swapped with another nucleotide
a wrong amino acid may be inserted into a protein
effects of substitution?
Missense mutation
Nonsense mutation
Splice Site mutation
what does a missense mutation result in?
where a single incorrect amino acid is inserted into a protein
what does a nonsense mutation result in?
the code for an amino acid is changed to a stop codon, resulting in a shorter protein
what does a splice site mutation result in?
some introns being retained and/ or some exons being removed
what happens insertion and what does it result in?
a certain number of nucleotides are added into a DNA molecule and all the triplets are read incorrectly
proteins made will have many different amino acids and may not work
what happens in deletion and what does it result in?
a certain number of nucleotides are remove from the DNA molecule and all the triplets are read incorrectly
proteins made will have many different amino acids and may not work
effects of insertion and deletion?
frame shift mutations
what is the problem with frame shift mutations?
all amino acids are affected and read incorrectly, as the order of bases change depending on the deletion/ insertion; therefore the amino acid will be different
major effect on structure of protein
how often do mutations occur
randomly and rarely
what is a chromosome mutation?
a change in the number or sequence of genes on a chromosome
4 types of chromosome mutations?
Translocation
Inversion
Duplication
Deletion
