1.6 Mutations Flashcards
Define a ‘Mutation’
A random irreversible change to an organism’s DNA sequence resulting in no protein or an altered protein be produced
What are the two possible results of a mutation?
- No protein produced
- Altered Protein
How can a mutation affect the phenotype?
Mutation will result in a change to amino acid sequence meaning altered protein / no protein produced. The proteins produced determines the phenotype. This means the phenotype is altered.
What are the three types of single gene mutations?
- Substitution
- Insertion
- Deletion
What are three types of substitution mutations?
- Missense
- Nonsense
- Splice Site
What is a missense substitution mutation?
Missense - causes the change to one amino acid
What is a splice site substitution mutation?
A mutation which changes the boundaries between exons and introns, resulting in introns staying in mature transcript
What is a nonsense substitution?
A mutation when one triplet is changed to form a stop codon
A nonsense mutation results in a … being produced which results in a shorter protein.
premature stop codon.
A nonsense mutation results in a premature stop codon being produced which results in a shorter protein.
What is the result of a missense mutation?
May result in a non-functional protein or have little a effect on the protein
What kind of substitution can result in a change to the mature mRNA transcript?
Splice site - results in introns being left in and alters final protein produced
What is a frame shift mutations?
Mutation resulting in all of the codons and all of the amino acids after the mutation to be changed
What type of single gene mutations result in a frame shift mutations?
Insertion
Deletion
What are the four types of chromosome mutations?
Duplication
Deletion
Inversion
Translocation
Describe an inversion chromosome mutation
An inversion mutation is where a segment of the chromosome breaks off, is inverted 180 degrees and attaches back onto the same chromosome
