Mutations Flashcards
What are mutations
changes in DNA that can result in no protein or altered protein being synthesised.
What are single gene mutations
involve the alteration of a DNA nucleotide
State the types of single gene mutation
the substitution of nucleotides. (replacing 1 nucleotide with another).
insertion of nucleotides.
deletion of nucleotides.
Describe missense mutations
result in one amino acid being changed for another. This may result in a non-functional protein or may have little effect on the protein depending on the amino acid that has been changed.
Describe nonsense mutations
result in premature stop codon being produced which results in a shorter protein.
Describe splice site mutations
result in some introns being retained and/or some exons not being included in the mature transcript.
What cause frame shift mutations
The effect of an insertion or deletion of a nucleotide results in frame shift mutations.
what is a frame shift mutation
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.
State the four types of chromosome mutations
Duplication
Deletion
Inversion
Translocation
Describe duplication
A section of a chromosome is added from its homologous partner
Describe deletion
A section of chromosome is removed
Describe inversion
a section of chromosome is reversed
Describe translocation
where a section of a chromosome is added to a chromosome, not its homologous partner.
what is the effect of chromosome mutations
The substantial changes in chromosome mutations often make them lethal.
