Unit 1.4 - Mutations Flashcards
What is Duplication?
Where a section of a chromosome is added from its homologous partner
What is a single gene mutations involve?
The alteration of a DNA nucleotide sequence as a result of the substitution, insertion or deletion of nucleotides
What does nucleotide insertion or deletion result in?
Frame shift mutations
What are the three nucleotides substitutions?
Missence, nonsense and splice - site
What is the effect of nonsense mutations?
Results in a premature stop codon being produced which results in a shorter protein
What is the effect of spice site mutations?
Results in some introns being retained and or some exons is not being included in the mature transcript
What are the chromosome structure mutations?
Duplications, deletion, inversion and translocation
What is deletion? And an example of a condition that it causes?
- Where a section of a chromosome is removed
* Cri-du-chat syndrome
What is inversion and what’s an example of a condition it causes?
- where a section of a chromosome is removed
* haemophilia A
What is translocation? And what’s and example of a condition it causes?
- where a section of a chromosome is added to a chromosome, not it’s homologous partner
- chronic myeloid leukaemia
What’s the effect of these substantial changes in chromosomes?
Makes them lethal
What is the definition of a mutation?
Changes in the DNA that can result in no proteins or and altred protein being synthesised
What do frameshift mutations cause?
- All of the codons and all of the amino acids after the mutations to be changed
- This has a major effect on the structure of the protein produced
What is the effect of missense mutation?
- Results in one amino acid being changed for another
* This may result in a non functional protein or have little effect of the protein
