Mutations 1.4 Flashcards
What are mutations
Mutations are changes in the DNA that can result in no protein or an altered protein being synthesised
What is a single gene mutation
Single gene mutations involve the alteration of a DNA nucleotide sequence as a result if the substitution, insertion or deletion of nucleotides
What are the three types of single gene mutations
Substitution
Insertion
Deletion
What is substitution
Substitution results in a change that only affect one codon
What are three examples of substitution
Missense mutation
Nonsense mutation
Splice site mutation
What is missense
One nucleotide is changed resulting in one amino acid being changed for another
What is the result of a missense mutation
Non functional protein or have little effect on the protein
What is a nonsense mutation
A stop codon is produced prematurely
What is the result of a nonsense mutation
Protein will be shorter and may be non functional
What is a splice site mutation
Some introns may be retained or some exons excluded
What is a result of a splice site mutation
The correct protein may not be produced
What is insertion
When a new base is added/inserted into the sequence causing a frame shift changing all the amino acids
What is deletion
Removing a nucleotide causing a frameshift which moves the bases causing a change in all the amino acids
What is a frameshift
When a base gets added/removed and all the bases move causing a change in all the amino acids
What is chromosome structure mutations
Chromosome structure mutations are alterations that affect whole chromosomes and whole genes rather than just individual nucleotides
