1.6 Mutations Flashcards
What is a mutation?
A change in the DNA that can result in no protein or an altered protein being synthesised
Give examples of single gene mutations?
substitution, insertion or deletion of nucleotides
What can nucleotide substitutions result in?
missense, nonsense and splice-site mutations
What is a missense mutation?
Missense mutations result in one amino acid being changed for another. This may result in a non-functional protein or have little effect on the protein
What is a nonsense mutation?
Nonsense mutations result in a premature stop codon being produced which results in a shorter protein
What is a splice-site mutation?
Splice-site mutations result in some introns being retained and/or some exons not being included in the mature transcript
What can nucleotide insertions or deletions result in?
Frame-shift mutations
What are frame-shift mutations?
Frame-shift mutations cause all of the codons and all of the amino acids after the mutation to be changed. This has a major effect on the structure of the protein produced
Give examples of chromosome structure mutations
Duplication, deletion, inversion and translocation.
What is a duplication mutation?
Duplication is where a section of a chromosome is added from its homologous partner
What is a deletion mutation?
Deletion is where a section of a chromosome is removed
What is a inversion mutation?
Inversion is where a section of chromosome is reversed
What is a translocation mutation?
Translocation is where a section of a chromosome is added to a chromosome not its homologous partner
What is the importance of mutation and gene duplication in evolution?
Duplication allows potential beneficial mutation to occur in a duplicated gene whilst the original gene can still be expressed to produce its protein
