Unit 1 - KA6 - Mutations Flashcards
Changes in the genome which can result in no protein or an altered protein being expressed.
Mutations
Alteration of a DNA nucleotide sequence.
Single gene mutation
One nucleotide is replaced by another nucleotide, only one amino acid is affected.
Substitution
One nucleotide is removed from the sequence, whole protein is affected.
Deletion
An extra nucleotide is added to the sequence, whole protein is affected
Insertion
Occurs after a substitution, where the altered codon codes for an amino acid which still makes sense, but not the original sense.
Missense
Occurs after a substitution, where the codon used to code for an amino acid but now codes for a stop codon.
Non sense
A mutation which causes one or more nucleotides to be inserted, substituted or deleted from a site of the sequence where introns are usually removed.
Splice site mutation
Mutations which cause a change in the whole sequence after the mutation site (deletion or insertion)
Frame shift mutations
Alteration to the structure of one or more chromosomes
Chromosome structure mutation
A section of a chromosome becomes detached and the information is lost.
Deletion
A section of DNA is repeated on the chromosome
Duplication
A section of the chromosome detaches, turns 180° and reattaches.
Inversion
A section of one chromosome becomes detached and joins onto a different chromosome
Translocation
These occur due to mutations and are the only source of new variation for living organisms, which makes them the raw material for evolution.
New alleles
