1.4 Flashcards
What are mutations ?
random changes to the DNA and can result in no protein or an altered protein being synthesised.
What are single gene mutations?
involve the alteration of a DNA nucleotide sequence as a result of the substitution, insertion or deletion of nucleotides.
The impact can either be minor or major depending on the type of mutation.
What is substitution ? (SGM)
Base(s) are switched.
What is deletion? (SGM)
Base is deleted, will shift the reading frame and all amino acids ‘upstream’.
What is insertion?
Base is added in, will shift the reading frame and all amino acids ‘downstream’.
What is 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 of the structure of the protein produced.
What types of mutations can cause a frameshift?
Insertion and deletion
What is missense mutations?
The amino acid code has been altered to a different amino acid. This could change protein shape, resulting in a non-functional protein or have no effect.
What is a nonsense mutation?
The change in code creates a stop codon.
The protein will be shorter and may be non-functional
What is a splice-site mutation?
result in some introns being retained and/or some exons not included in the mature transcript.
What are chromosomal mutations?
often lethal or have major impacts on a variety of bodily functions due to the substantial changes.
What is Deletion?
where a section of a chromosome is
removed.
What is Duplication?
where a section of chromosome is
added from its homologous partner.
What is inversion?
where a section of chromosome is
reversed.
What is translocation?
where a section of a chromosome is
added to a chromosome, (not its homologous
partner).
