UNIT 1: Key area 6 - -mutations Flashcards
what is a mutation ?
changes of DNA that can result in no protein or changed protein being synthesised
define single gene mutation
involves alteration of DNA nucleotide sequence
when does single gene mutations occur ?
substitution
insertion
or deletion of nucleotides
effect of substitution mitation
mis sense
nonsense
and splice site mutations
explain mis sense mutation
codon codes for a different amino acid
resulting in a non functional protein
explain nonsense mutation
amino acid that used to be coded for is not a stop codon
causing a shortened protein
usually non functional
what do splice site mutations result in ?
intone being retained and some exons not being included in mature transcript
can be translated into altered protein which won’t function properly
what does insertion and deletion cause ?
frameshift mutations
what does frame shift mutations cause ?
all codons and amino acids after the mutation to be changed
institution mean what for the base ?
base is added
deletion means what for the base ?
base is removed
frame shift mutation means what ?
base is inserted or deleted affecting every amino acid after mutation
causing the protein formed to be almost certainly non functional
name the four types of structure mutations
deletion of genes
duplication
inversion
translocation
deletion is where …?
and what affect does this have ?
a section of chromosome is removed
genes are then lost
duplication is where …?
a section of a chromosome is added from its homologous partner
