Mutations Flashcards
What is a mutation?
A change in the DNA
What is the possible result of a mutation?
No protein being made or an altered protein being synthesised
What do we call mutations that involve the alteration of a DNA nucleotide sequence?
SIngle gene mutation
State the 3 types of single gene mutation.
deletion, insertion, substitution
Describe a deletion mutation.
One or more nucleotides are removed.
Describe an insertion mutation.
One or more nucleotides are added.
Describe a substitution mutation.
Where on nucleotide is replaced with another.
Which of the single gene mutations are described as frameshift?
deletion and insertion
What does a frameshift mutation result in?
Potentially every amino acid after the mutation is changed.
What do we call a mutation where one amino acid is replaced with another?
missense
What is the end result of a missense mutation?
non-functional protein or little effect on the protein
What is a nonsense mutation?
premature stop codon therefore shorter protein
Name the sections that are removed during RNA splicing?
introns - IN the bIN
Name the sections that are EXpressed after RNA splicing.
EXons
What is a splice site mutation?
When some introns are retained and/or some exons are removed
What is the result of a splice site mutation?
A different mature transcript being produced
Name the 4 types of chromosomal mutation.
duplication, deletion, inversion and translocation
What is a duplication mutation?
Where a section of a chromosome is added from its homologous partner
What is a chromosomal deletion mutation?
Where a section of a chromosome is removed
What is an inversion mutation?
Where a section of chromosome is reversed
What is a translocation mutation?
A section of chromosome is added, NOT to its homologous partner
What is often the consequence of a chromosomal mutation?
death (lethal)
What is the only source of new alleles?
mutations
Which form of mutation allows potentially beneficial mutations to occur whilst also the original gene can be expressed and protein made?
duplication
